Amino acids are, on the one hand, the smallest building blocks of a protein, but on the other hand they also fulfill independent functional tasks. Those amino acids that are used to build proteins are called “proteinogenic”.

A distinction is also made between essential and non-essential amino acids:

• Essential amino acids: Must be supplied through food; An undersupply cannot be compensated for by the body itself
• Non-essential amino acids: Can be formed in the organism using essential amino acids

 

To date, over 400 amino acids are known, 20 of which are “proteinogenic” in humans - i.e.H serve to build proteins. And 9 of the >400 amino acids are “essential”, i.e.H must be supplied through food and cannot be produced by the body itself.

Amino acids are fatty acid derivatives (carboxylic acid derivatives) with an amino group on the α-C atom (“α-amino carboxylic acids”)

 

Classification of amino acids

• By chemical structure
  • branched-chain or non-branched-chain
  • sulfur-containing or non-sulfur-containing
  • aromatic (with a benzene ring of 6 carbon atoms in the side chain) or aliphatic (not aromatic)
• By essentiality
  • Essential/semi-essential AS (must be administered)
  • Non-essential AS (can e.g.b are formed in the citrate cycle by transamination from 2-oxocarboxylic acids)
• By tasks
  • Functional tasks:
    • Structural tasks (anabolic function): Construction of oligopeptides and proteins (currently 23 amino acids recognized, e.g.b ornithine, citrulline, taurine)
    • Energy production (catabolic function)
    • Provision of sulfur
  • Medical tasks:
    • Prevention, e.g.b Hormone replacement therapy (L-arginine)
    • Therapy, e.g.b Immunology, oxidative stress, cardiology, psyche

The most important amino acids

a) Essential

• Isoleucine (VK, k, g, *)
• Leucine (VK, k, *)
• Lysine (k, *)
• Methionine (SH, g, *)
• Phenylalanine (AS, k, g, *)
• Threonine (g, *)
• Tryptophan (AS, k, g, *)
• Valine (VK, g, *)
• Histidine (AS, g, *

b) Semi-essential

• Arginine (g *)
• Cystine/cysteine ​​(SH, g, *)
• Tyrosine (AS, k, g, *)

c) Non-essential

• Alanine (g, *)
• Aspartic acid/
• Asparagine (g, *)
• Glutamic acid (g, *)
• Glutamine (g, *)
• Glycine (glycocol, g, *)
• Serine (g, *)
  Proline (g, *)
  Ornithine
• Taurine (SH)
• Hydroxyproline
• Citrulline
• 3-Methylhistidine
• GABA
• Theanine

* = AS used for protein synthesis
k = ketogenic
g = glycogen
SH = Sulfur-containing AS
VK = Branched-chain AS
AS = Aromatic AS

 

Catabolic vs anabolic pathway

Digestible proteins that are consumed through food are broken down into their components (amino acids) and added to the amino acid pool. The amino acids are then utilized either “catabolic” or “anabolic”. The catabolic pathway describes the use of amino acids for energy production in the mitochondria; the anabolic pathway describes the use of amino acids to build proteins.

 

Functions of proteins (formed from amino acids) in humans

Protein	Function	Examples
Structural proteins	support structure of the organism	Collagen, hair, nails, matrix, elastin, keratin, myosin
Contractile proteins	Components of the muscles	Myosin, Actin
Enzymes	Catalysis of many biochemical reactions, antioxidant and anti-inflammatory function	Amylase, lipase, pepsin, trypsin, catalases, peroxidases, proteases
Transport and carrier proteins	Transportation of important molecules	Hemoglobin, plasma albumins, calcium binding protein, metallothioneins
Regulation proteins	Control and coordination of chemical reactions	Hormones (e.g.b Insulin, oxytocin, insulin, glucagon, corticotropin, vasopressin, angiotensin)
Protective proteins	Storage of substances for future use	Blood coagulation (thrombin, fibrin, fibrinogen), immune system (immunoglobulins, interleukins), storage proteins (ferritin = iron storage)
Control proteins	Regulation of various processes in the organism	Correct reading of the DNS

 

Amino acids as precursors of the body's own substances

Precursors of other AS derivatives (oligopeptides)
Lysine + Methionine	Carnitine
Phenylalanine + Tyrosine	Coenzyme Q10
Glutamate + glycine + cysteine	Glutathione
Arginine + glycine (+ cofactor methionine)	Creatine (methylguanidine acetic acid)
Cysteine ​​(+ Vit B5 + ADP)	Coenzyme A
Glutamate + glycine + cysteine ​​(+ Vit B3 + chromium)	Glucose tolerance factor
Arginine, Ornithine (+ SAM)	Polyamines (spermidine, putrescine, spermine)
Arginine	Nitrogen monoxide (NO)

 

Precursors of neurotransmitters (biogenic amines)
Phenylalanine -> Tyrosine	Adrenaline, norepinephrine, thyroxine, tyramine (sympathomimetic)
Tryptophan	Serotonin, Melatonin
Histidine	Histamine
Glutamic acid (glutamate)	Gamma-aminobutyric acid (GABA), glutamine

 

 

The most important amino acids at a glance

L-Lysine

• Essential amino acid
• Basic amino acid
• Carnitine building block (cofactors Fe, Vit. C, B3)
• Effects:
  • Cardiovascular protective function: building block of vascular collagen, atherogenic potential of Lp(a) â, possibly. Release of deposited Lp(a)'s
  • Important for the immune system (v.a in viral infections (reduces virus replication))
  • Increases intestinal Ca++ absorption (possibly. useful for osteoporosis)

L-Methionine

• Essential amino acid
• Neutral sulfur-containing amino acid (main source of sulfur)
• S-Adenosyl-Methionine (SAM) = biologically active form
• Precursor of homocysteine ​​and thus of cysteine, cystine, taurine (B vitamins and methionine are essential for homocysteine ​​metabolism and 1-carbon pathway!)
• Building block of carnitine
• Effects:
  • Most important methyl group donor and therefore highly relevant in the context of epigenetics and longevity research (“healthy longevity”)
  • binds heavy metals for detoxification (e.g.b copper, cadmium and mercury)
  • acidifies the urine
  • has an antioxidant effect (supports selenium effect)
  • important for immune system

 

L-Tryptophan

• essential amino acid
• Aromatic amino acid
• Precursor of serotonin (and melatonin)
• Precursor stage of kynurenine formation
• Effects:
  • Sleep-promoting
  • Immune system
    • Antibody response via Kynurenine
    • Monocytes and IL1 production á
  • Formation of vitamin B3 (niacin) or NAD via kynurenine (especially in the liver)
  • Formation of proteins and acetyl-CoA
  • Lowers blood pressure (especially in combination with Vit. B6): probably due to serotonergic effects
• Risk of deficiency e.g.b for fructose intolerance and lactose intolerance (reduced absorption in the intestine), as undigested lactose binds tryptophan and prevents its absorption
  (source: www.fxmayr.com/de/medizin-ernaehrung-lactose.aspx; https://vgxii.com/attack-of-the-tryptophan/)

Tryptophan-serotonin-melatonin synthesis

 

L-Arginine

• Semi-essential amino acid
• Basic amino acid formed from citrulline and aspartate or from ornithine
• Effects:
  • Precursor of nitrogen monoxide (NO)
    • Signal substance
    • antioxidant, cytotoxic, antimicrobial, stimulation of neutrophil leukocytes
    • vasodilating, reduces platelet aggregation and blood pressure, improves blood circulation (similar to prostaglandin E1)
  • Stimulates anabolic somatotropin (STH = “fasting hormone”); STH increases protein synthesis and mobilizes fat depots
  • Stimulates anabolic insulin like growth factor 1 (IGF-1)
  • Important for (cellular) immune system
  • Important for collagen synthesis
  • Improves perfusion after ischemia
• Practical tip:
  • Fractional administration in several small doses between meals
  • Herpes proteins rich in arginine (possibly. Activation of latent infections):
    therefore arginine is not used as monotherapy in herpes simplex infections:
    Combination with lysine (acute 3x1 g/day, preventive 500 mg/day) in a ratio of 1:2

 

L-Carnitine

• Amino acid derivative
• Formation from methionine and lysine
• Effects:
  • Energy metabolism (L-carnitine as a “biocarrier”): Transport molecule for free long-chain FAs in mitochondria for beta-oxidation (95% of the occurrence in heart and skeletal muscles)
  • Performance-enhancing (e.g.b Sports, cardiology)
  • Influence on blood lipid levels
  • membrane stabilizing, antioxidant and neuroprotective
  • Important for immune system
  • Detoxification function: Hepatic metabolism of toxic substances; Transport molecule (“biocarrier”) of the toxic metabolites for excretion via the kidneys

 

Coenzyme Q10

• Amino acid derivative
• Formation from geranylgeranyl phosphate (from mevalonic acid pathway or Acetyl-CoA via all-trans-decaprenyl phosphate) and from tyrosine (via hydroxybenzoic acid)
• Effects:
  • Energy metabolism: Central component of the respiratory chain (inner mitochondrial membrane)
  • Antioxidant in lipophilic phase (concerning arteriosclerosis, cancer, accelerated aging, etc.)
    • Localization in mitochondria: particularly good and rapid local effect on oxygen radicals
    • Involved in the reduction of oxidized vitamin E
  • Caution: Statin administration reduces coenzyme Q-10 formation (from mevalonic acid)

 

Examples of amino acid (and derivatives) indications

 A) Immune system

• Amino acids are building blocks of immune cells
• Amino acids are building blocks of:
  • Immunoglobulins
  • Interferons (antiviral and antiproliferative glycoproteins of leukocytes)
  • Interleukins (stimulate growth and differentiation of lymphocytes)
  • Lysozyme (dissolves bacterial walls)
  • Thymus factors (stimulate maturation of T lymphocytes and proliferation of lymphatic tissue)
• Amino acids (and derivatives) have an antioxidant effect
• Amino acids stabilize the non-specific mucosa block
• Amino acids affect T cell regulation
• Amino acids stimulate the specific humoral immune response
• Tryptophan is a kynurenine precursor

Substance	Effect examples
Arginine	T cell stimulation, phagocytosis modulation (neutrophils, monocytes), antimicrobial, Regulation of cytokine production
Lysine	Regulation of NO
Methionine	Methyl group donor in the immune system
Taurine	anti-inflammatory
Threonine	Stimulation of lymphocyte proliferation, synthesis of mucus protein in the intestinal immune system,
Tryptophan	Inhibition of pro-inflammatory cytokines, production of kynurenines, increase of immunity
Carnitine	T cell stimulation, phagocytosis modulation (neutrophils, monocytes)
Glutathione	Regulation of cell metabolism (e.g.b Leukotriene formation, apoptosis), immune response
Creatine	Antiviral activity

(Source: Arndt & Albers, Handbook Protein and Amino Acids, p. 55, Li P et al.; Amino acids and immune function. Br J Nutr 2007;98(2):237-52)

 

B) Diabetes

• Increased use of amino acids for gluconeogenesis (amino acids as energy sources)
• Increased formation of fatty acids and ketone bodies from amino acids (due to high amounts of acetyl-CoA and overtaxing of the citrate cycle)
• Amino acid derivatives have an antioxidant effect (at high oxidative stress)
• Amino acids can stimulate insulin secretion (insulin improves amino acid uptake in cells)
• Insulin (peptide hormone) contains disulfide bridges and requires sulfur
• Important amino acids in diabetes:
  • L-Carnitine (reduces acetyl-CoA and lowers ketone bodies)
  • L-arginine, phenylalanine, BCAA (insulin release)
  • L-cysteine ​​(anda Component GTF, essential for CoA formation, S supplier)
  • Aspartic acid (lowers ketones)
  • Glutathione, taurine (antioxidant, S-supplier)

 

C) Cardiovascular system

• Amino acids are relevant to the cardiovascular system
  • Vasodilation (“expansion” of blood vessels)
  • Vascular protection
  • Energy supply
  • Radical degradation and reduction of lipid peroxidation
• Important amino acids for the cardiovascular system:
  • L-Arginine (NO and vasodilation)
  • L-cysteine ​​(improves NO function)
  • Taurine (positive inotropic, antiarrhythmic, antioxidant)
  • L-Lysine (stabilizes vessel walls, reduces atherogenic potential of Lp(a))
  • L-tryptophan and tyrosine (RR-lowering neurotransmitters)
  • L-carnitine and coenzyme Q10 (energy)
  • Glutathione (antioxidant)

 

D) Liver

• Amino acids prevent destruction of the (liver) cell membrane
• Formation of structural proteins (e.g.b Liver cell membrane)
• Formation of liver-specific enzymes and functional proteins
• Amino acids maintain complex detoxification functions: Liver must detoxify ammonia in the urea cycle (formed during protein catabolism)
• Important amino acids for the liver:
• L-arginine, ornithine, aspartic acid, citrulline
• L-cysteine ​​(sulfate, glutathione)
• Branched-chain AS (in cirrhosis)

 

E) Gastrointestinal tract

• Proteins are broken down in the gastrointestinal tract:
  • Protein digestion begins in the stomach
  • Pepsin as a key enzyme (acid-controlled)
  • Peptones as cleavage products (stimulate duodenal cholecystokinin and exocrine pancreas)
• Absorption disorders (e.g.b due to illnesses) lead to amino acid deficiency
• Intestine, in turn, requires amino acids for its function (e.g.b Cell membrane structure, energy for intestinal flora, detoxification, bile acid metabolism)
• Important amino acids (derivatives) with intestinal mucosa-protecting and digestive effects: Methionine, glutamine, histidine, threonine, tryptophan and glutathione

Lead amino acids (and derivatives) in the gastrointestinal tract

Substance	Functions & Effects
Methionine	Cofactor in the formation of melatonin and CoA (involved in the formation of cell membrane phospholipids in the intestinal mucosa) Important for Formation of active short-chain fatty acids (formed by physiological intestinal flora with mucosa-protective and anti-carcinogenic properties) Important for barrier function and integrity of the colon mucosa
Glutamine	Main energy source of the mucosal cells and precursor for the nucleotide biosynthesis of the rapidly dividing intestinal mucosa cells. Improves intestinal mucosa. As a result of metabolic stress (surgery, burns, trauma), glutamine deficiency often occurs, which leads to mucosal atrophy with reduced barrier function and facilitated bacterial translocation
Histidine	Influences gastric acidity and is the starting substance for the formation of histamine (biogenic amine with many biological effects). Increases hydrochloric acid secretion
Threonine	Promotes mucosa integrity and barrier function
Tryptophan	Precursors of serotonin and indole (derivatives), which support barrier function and mucosal homeostasis and nervous system
Glutathione (cysteine, glycine, glutamic acid)	Essential for maintaining normal intestinal mucosa. Antioxidant. Important for detoxification. Illnesses and noxious substances such as celiac disease, cigarette smoke, cytostatics and NSAIDs worsen the intestinal glutathione balance

 

F) Psyche

• Precursors and activators of neurotransmitters (L-tryptophan, L-phenylalanine, L-tyrosine, L-histidine)
• Effects as a neurotransmitter (e.g.b Glutamine, glutamate, GABA, glycine)
• Involved in the metabolism of melatonin (SAM, L-tryptophan)
• Involved as protein precursors in stress processing, hypothalamic-pituitary-NNR axis and sleep

Neurotransmitters	Precursor	Function / Control
L-Glycine	L-Serine	inhibitory effect on brain activity (anxiolysis, sedation)
L-glutamic acid (glutamate)	L-Glutamine	Excitatory NTM (brain alertness); important for neuroplasticity
L-Glutamine	L-glutamic acid (glutamate)	Can be converted into glutamic acid; Precursor of GABA; important for cellular immune defense
GABA (γ-aminobutyric acid)	L-glutamic acid (glutamate)	Inhibitory NTM (sleep-promoting, anxiolytic, sedating, HGH-stimulating)
Adrenaline/Norepinephrine	L-phenylalanine/L-tyrosine	More excitatory NTM
Serotonin	L-Tryptophan	More inhibitory NTM
Histamine	L-Histidine	Has a regulating effect on noradrenergic, serotoninergic, cholinergic, dopaminergic and glutaminergic neurons; influences the release of other NTM via presynaptic H3 receptors

 

 

G) Weight reduction

• Weight reduction means: reducing calorie intake; Consequences:
  • Lower protein intake
  • Gluconeogenesis and fatty acid production from amino acids á
  • Degradation of structural proteins (muscles, enzymes, immunoglobulins, transport albumin) à reduced performance, tiredness, exhaustion, premature “diet termination”
  • Colloid osmotic pressure decreases with edema formation and reduced diuresis (amino acids regulate water balance)
  • Important amino acids as part of a diet:
    • Neurotransmitters and precursors (e.g.b Tryptophan, phenylalanine, glutamine, taurine)
    • Arginine (activation of the somatotrophic hormone STH à reduces fat mass)
    • Carnitine (fat burning)

 

H) Sport / Performance

• Structural development (especially muscles)
• Optimization of metabolism (e.g.b Immune system, redox system, psyche)
• Energy generation (incl. reserve energy)
• Antioxidant effect (high levels of radicals during extreme sports
• Important amino acids to increase performance:
  • L-Carnitine (Energy)
  • Coenzyme Q 10 (energy)
  • Creatine (Energy)
  • Glutathione (antioxidant)
  • Essential AS esp. branched chain AS as well as arginine, glutamine (structure structure)

 

I) Healthy longevity (“Longevity”)

• A good supply of amino acids is a useful building block in an overall “good aging” concept.
  • Amino acids include:a Building blocks of proteins and other essential substances
  • Optimization of metabolism (e.g.b Immune system, redox system, psyche, hormones)
  • Optimization of the supporting tissue
  • Optimization of organ functions (e.g.b Cardiovascular, nerves, skin)
• Important amino acids for “aging skin” (e.g.b

  Amino acids are, on the one hand, the smallest building blocks of a protein, but on the other hand they also fulfill independent functional tasks. Those amino acids that are used to build proteins are called “proteinogenic”.

  A distinction is also made between essential and non-essential amino acids:

  • Essential amino acids: Must be supplied through food; An undersupply cannot be compensated for by the body itself
  • Non-essential amino acids: Can be formed in the organism using essential amino acids

   

  So far, over 400 amino acids are known, of which 20 are “proteinogenic” in humans – i.e. used to build proteins. And 9 of the >400 amino acids are “essential”, i.e. must be supplied through food and cannot be produced by the body itself.

  Amino acids are fatty acid derivatives (carboxylic acid derivatives) with an amino group on the α-C atom (“α-amino carboxylic acids”)

  

   

  Classification of amino acids

  • By chemical structure
    • branched-chain or non-branched-chain
    • sulfur-containing or non-sulfur-containing
    • aromatic (with a benzene ring of 6 carbon atoms in the side chain) or aliphatic (not aromatic)
  • By essentiality
    • Essential/semi-essential AS (must be administered)
    • Non-essential AS (can be formed, for example, in the citrate cycle by transamination from 2-oxocarboxylic acids)
  • By tasks
    • Functional tasks:
      • Structural tasks (anabolic function): Construction of oligopeptides and proteins (currently 23 amino acids recognized, e.g. ornithine, citrulline, taurine)
      • Energy production (catabolic function)
      • Provision of sulfur
    • Medical tasks:
      • Prevention, e.g. hormone replacement therapy (L-arginine)
      • Therapy, e.g. immunology, oxidative stress, cardiology, psyche

  The most important amino acids

  a) Essential

  • Isoleucine (VK, k, g, *)
  • Leucine (VK, k, *)
  • Lysine (k, *)
  • Methionine (SH, g, *)
  • Phenylalanine (AS, k, g, *)
  • Threonine (g, *)
  • Tryptophan (AS, k, g, *)
  • Valine (VK, g, *)
  • Histidine (AS, g, *
  b) Semi-essential
  
  • Arginine (g *)
  • Cystine/cysteine ​​(SH, g, *)
  • Tyrosine (AS, k, g, *)
  c) Non-essential
  
  • Alanine (g, *)
  • Aspartic acid/
  • Asparagine (g, *)
  • Glutamic acid (g, *)
  • Glutamine (g, *)
  • Glycine (glycocol, g, *)
  • Serine (g, *)
    Proline (g, *)
    Ornithine
  • Taurine (SH)
  • Hydroxyproline
  • Citrulline
  • 3-Methylhistidine
  • GABA
  • Theanine

  * = AS used for protein synthesis
  k = ketogenic
  g = glycogen
  SH = Sulfur-containing AS
  VK = Branched-chain AS
  AS = Aromatic AS

   

  Catabolic vs anabolic pathway

  Digestible proteins that are consumed through food are broken down into their components (amino acids) and added to the amino acid pool. The amino acids are then utilized either “catabolic” or “anabolic”. The catabolic pathway describes the use of amino acids for energy production in the mitochondria; the anabolic pathway describes the use of amino acids to build proteins.

  

   

  Functions of proteins (formed from amino acids) in humans

  Protein	Function	Examples
  Structural proteins	support structure of the organism	Collagen, hair, nails, matrix, Elastin, keratin, myosin
  Contractile proteins	Components of the muscles	Myosin, Actin
  Enzymes	Catalysis of many biochemical reactions, antioxidant and anti-inflammatory function	Amylase, lipase, pepsin, trypsin, catalases, peroxidases, proteases
  Transport and carrier proteins	Transportation of important molecules	Hemoglobin, plasma albumins, calcium binding protein, metallothioneins
  Regulation proteins	Control and coordination of chemical reactions	Hormones (e.g. insulin, oxytocin, insulin, glucagon, corticotropin, vasopressin, angiotensin)
  Protective proteins	Storage of substances for future use	Blood coagulation (thrombin, fibrin, fibrinogen), immune system (immunoglobulins, interleukins), storage proteins (ferritin = iron storage)
  Control proteins	Regulation of various processes in the organism	Correct reading of the DNS

   

  Amino acids as precursors of the body's own substances

  Precursors of other AS derivatives (oligopeptides)
  Lysine + Methionine	Carnitine
  Phenylalanine + Tyrosine	Coenzyme Q10
  Glutamate + glycine + cysteine	Glutathione
  Arginine + glycine (+ cofactor methionine)	Creatine (methylguanidine acetic acid)
  Cysteine ​​(+ Vit B5 + ADP)	Coenzyme A
  Glutamate + glycine + cysteine ​​(+ Vit B3 + chromium)	Glucose tolerance factor
  Arginine, Ornithine (+ SAM)	Polyamines (spermidine, putrescine, spermine)
  Arginine	Nitrogen monoxide (NO)

   

  Precursors of neurotransmitters (biogenic amines)
  Phenylalanine -> Tyrosine	Adrenaline, norepinephrine, thyroxine, tyramine (sympathomimetic)
  Tryptophan	Serotonin, Melatonin
  Histidine	Histamine
  Glutamic acid (glutamate)	Gamma-aminobutyric acid (GABA), glutamine

   

   

  The most important amino acids at a glance
  
  

  L-Lysine

  • Essential amino acid
  • Basic amino acid
  • Carnitine building block (cofactors Fe, Vitamin C, B3)
  • Effects:
    • Cardiovascular protective function: building block of vascular collagen, atherogenic potential of Lp(a) â, possible release of deposited Lp(a)'s
    • Important for the immune system (especially in viral infections (reduces virus replication))
    • Increases intestinal Ca++ absorption (possibly useful in osteoporosis)

  L-Methionine

  • Essential amino acid
  • Neutral sulfur-containing amino acid (main source of sulfur)
  • S-Adenosyl-Methionine (SAM) = biologically active form
  • Precursor of homocysteine ​​and thus of cysteine, cystine, taurine (B vitamins and methionine are for the homocysteine ​​metabolism and 1-carbon pathway essential!)
  • Building block of carnitine
  • Effects:
    • Most important methyl group donor and therefore highly relevant in the context of epigenetics and longevity research (“healthy longevity”)
    • binds heavy metals for detoxification (e.g. copper, cadmium and mercury)
    • acidifies the urine
    • has an antioxidant effect (supports selenium effect)
    • important for immune system

   

  L-Tryptophan

  • essential amino acid
  • Aromatic amino acid
  • Precursor of serotonin (and melatonin)
  • Precursor stage of kynurenine formation
  • Effects:
    • Sleep-promoting
    • Immune system
      • Antibody response via Kynurenine
      • Monocytes and IL1 production á
    • Formation of vitamin B3 (niacin) or NAD via kynurenine (especially in the liver)
    • Formation of proteins and acetyl-CoA
    • Lowers blood pressure (especially in combination with vitamin B6): probably due to serotonergic effects
  • Risk of deficiency, e.g. in fructose intolerance and lactose intolerance (reduced absorption in the intestine), as undigested lactose binds tryptophan and prevents its absorption
    (Source: www.fxmayr.com/de/medizin-ernaehrung-lactose.aspx; https://vgxii.com/attack-of-the-tryptophan/)

  Tryptophan-serotonin-melatonin synthesis

   

  L-Arginine

  • Semi-essential amino acid
  • Basic amino acid formed from citrulline and aspartate or from ornithine
  • Effects:
    • Precursor of nitrogen monoxide (NO)
      • Signal substance
      • antioxidant, cytotoxic, antimicrobial, stimulation of neutrophil leukocytes
      • vasodilating, reduces platelet aggregation and blood pressure, improves blood circulation (similar to prostaglandin E1)
    • Stimulates anabolic somatotropin (STH = “fasting hormone”); STH increases protein synthesis and mobilizes fat depots
    • Stimulates anabolic insulin like growth factor 1 (IGF-1)
    • Important for (cellular) immune system
    • Important for collagen synthesis
    • Improves perfusion after ischemia
  • Practical tip:
    • Fractional administration in several small doses between meals
    • Herpes proteins rich in arginine (possibly activation of latent infections):
      Therefore, arginine is not used as monotherapy in herpes simplex infections:
      Combination with lysine (acute 3x1 g/day, preventive 500 mg/day) in a ratio of 1:2

  
  
  

   

  L-Carnitine

  • Amino acid derivative
  • Formation from methionine and lysine
  • Effects:
    • Energy metabolism (L-carnitine as a “biocarrier”): Transport molecule for free long-chain FAs in mitochondria for beta-oxidation (95% of the occurrence in heart and skeletal muscles)
    • Performance-enhancing (e.g. sports, cardiology)
    • Influence on blood lipid levels
    • membrane stabilizing, antioxidant and neuroprotective
    • Important for immune system
    • Detoxification function: Hepatic metabolism of toxic substances; Transport molecule (“biocarrier”) of the toxic metabolites for excretion via the kidneys

   

  Coenzyme Q10

  • Amino acid derivative
  • Formation from geranylgeranyl phosphate (from mevalonic acid pathway or acetyl-CoA via all-trans-decaprenyl phosphate) and from tyrosine (via hydroxybenzoic acid)
  • Effects:
    • Energy metabolism: Central component of the respiratory chain (inner mitochondrial membrane)
    • Antioxidant in lipophilic phase (concerning arteriosclerosis, cancer, accelerated aging, etc.)
      • Llocalization in mitochondria: particularly good and rapid local effect on oxygen radicals
      • Involved in the reduction of oxidized vitamin E
    • Caution: Statin administration reduces coenzyme Q-10 formation (from mevalonic acid)

   

  Examples of amino acid (and derivatives) indications

   A) Immune system

  • Amino acids are building blocks of immune cells
  • Amino acids are building blocks of:
    • Immunoglobulins
    • Interferons (antiviral and antiproliferative glycoproteins of leukocytes)
    • Interleukins (stimulate growth and differentiation of lymphocytes)
    • Lysozyme (dissolves bacterial walls)
    • Thymus factors (stimulate maturation of T lymphocytes and proliferation of lymphatic tissue)
  • Amino acids (and derivatives) have an antioxidant effect
  • Amino acids stabilize the non-specific mucosa block
  • Amino acids affect T cell regulation
  • Amino acids stimulate the specific humoral immune response
  • Tryptophan is a kynurenine precursor

  Substance	Effect examples
  Arginine	T cell stimulation, phagocytosis modulation (neutrophils, monocytes), antimicrobial, Regulation of cytokine production
  Lysine	Regulation of NO
  Methionine	Methyl group donor in the immune system
  Taurine	anti-inflammatory
  Threonine	Stimulation of lymphocyte proliferation, synthesis of mucus protein in the intestinal immune system,
  Tryptophan	Inhibition of pro-inflammatory cytokines, production of kynurenines, increase of immunity
  Carnitine	T cell stimulation, phagocytosis modulation (neutrophils, monocytes)
  Glutathione	Regulation of cell metabolism (e.g. leukotriene formation, apoptosis), immune response
  Creatine	Antiviral activity

  (Source: Arndt & Albers, Handbook Protein and Amino Acids, p. 55, Li P et al.; Amino acids and immune function. Br J Nutr 2007;98(2):237-52)

   

  B) Diabetes

  • Increased use of amino acids for gluconeogenesis (amino acids as energy sources)
  • Increased formation of fatty acids and ketone bodies from amino acids (due to high amounts of acetyl-CoA and overtaxing of the citrate cycle)
  • Amino acid derivatives have an antioxidant effect (at high oxidative stress)
  • Amino acids can stimulate insulin secretion (insulin improves amino acid uptake in cells)
  • Insulin (peptide hormone) contains disulfide bridges and requires sulfur
  • Important amino acids in diabetes:
    • L-Carnitine (reduces acetyl-CoA and lowers ketone bodies)
    • L-arginine, phenylalanine, BCAA (insulin release)
    • L-cysteine ​​(including component GTF, essential for CoA formation, S supplier)
    • Aspartic acid (lowers ketones)
    • Glutathione, taurine (antioxidant, S-supplier)

   

  C) Cardiovascular system

  • Amino acids are relevant to the cardiovascular system
    • Vasodilation (“expansion” of blood vessels)
    • Vascular protection
    • Energy supply
    • Radical degradation and reduction of lipid peroxidation
  • Important amino acids for the cardiovascular system:
    • L-Arginine (NO and vasodilation)
    • L-cysteine ​​(improves NO function)
    • Taurine (positive inotropic, antiarrhythmic, antioxidant)
    • L-Lysine (stabilizes vessel walls, reduces atherogenic potential of Lp(a))
    • L-tryptophan and tyrosine (RR-lowering neurotransmitters)
    • L-carnitine and coenzyme Q10 (energy)
    • Glutathione (antioxidant)

   

  D) Liver

  • Amino acids prevent destruction of the (liver) cell membrane
  • Formation of structural proteins (e.g. liver cell membrane)
  • Formation of liver-specific enzymes and functional proteins
  • Amino acids maintain complex detoxification functions: Liver must detoxify ammonia in the urea cycle (formed during protein catabolism)
  • Important amino acids for the liver:
  • L-arginine, ornithine, aspartic acid, citrulline
  • L-cysteine ​​(sulfate, glutathione)
  • Branched-chain AS (in cirrhosis)

   

  E) Gastrointestinal tract

  • Proteins are broken down in the gastrointestinal tract:
    • Protein digestion begins in the stomach
    • Pepsin as a key enzyme (acid-controlled)
    • Peptones as cleavage products (stimulate duodenal cholecystokinin and exocrine pancreas)
  • Absorption disorders (e.g. due to illnesses) lead to amino acid deficiency
  • Intestine, in turn, requires amino acids for its function (e.g. cell membrane structure, energy for intestinal flora, detoxification, bile acid metabolism)
  • Important amino acids (derivatives) with intestinal mucosa-protecting and digestive effects: Methionine, glutamine, histidine, threonine, tryptophan and glutathione

  Lead amino acids (and derivatives) in the gastrointestinal tract

  Substance	Functions & Effects
  Methionine	Cofactor in the formation of melatonin and CoA (involved in the formation of cell membrane phospholipids in the intestinal mucosa) Important for Formation of active short-chain fatty acids (formed by physiological intestinal flora with mucosa-protective and anti-carcinogenic properties) Important for barrier function and integrity of the colon mucosa
  Glutamine	Main energy source of the mucosal cells and precursor for the nucleotide biosynthesis of the rapidly dividing intestinal mucosa cells. Improves intestinal mucosa. As a result of metabolic stress (surgery, burns, trauma), glutamine deficiency often occurs, which leads to mucosal atrophy with reduced barrier function and facilitated bacterial translocation
  Histidine	Influences gastric acidity and is the starting substance for the formation of histamine (biogenic amine with many biological effects). Increases hydrochloric acid secretion
  Threonine	Promotes mucosa integrity and barrier function
  Tryptophan	Precursors of serotonin and indole (derivatives), which support barrier function and mucosal homeostasis and nervous system
  Glutathione (cysteine, glycine, glutamic acid)	Essential for maintaining normal intestinal mucosa. Antioxidant. Important for detoxification. Illnesses and noxious substances such as celiac disease, cigarette smoke, cytostatics and NSAIDs worsen the intestinal glutathione balance

   

  F) Psyche

  • Precursors and activators of neurotransmitters (L-tryptophan, L-phenylalanine, L-tyrosine, L-histidine)
  • Acts as a neurotransmitter (e.g. glutamine, glutamate, GABA, glycine)
  • Involved in the metabolism of melatonin (SAM, L-tryptophan)
  • Involved as protein precursors in stress processing, hypothalamic-pituitary-NNR axis and sleep

  Neurotransmitters	Precursor	Function / Control
  L-Glycine	L-Serine	inhibitory effect on brain activity (anxiolysis, sedation)
  L-glutamic acid (glutamate)	L-Glutamine	Excitatory NTM (brain alertness); important for neuroplasticity
  L-Glutamine	L-glutamic acid (glutamate)	Can be converted into glutamic acid; Precursor of GABA; important for cellular immune defense
  GABA (γ-aminobutyric acid)	L-glutamic acid (glutamate)	Inhibitory NTM (sleep-promoting, anxiolytic, sedating, HGH-stimulating)
  Adrenaline/Norepinephrine	L-phenylalanine/L-tyrosine	More excitatory NTM
  Serotonin	L-Tryptophan	More inhibitory NTM
  Histamine	L-Histidine	Has a regulating effect on noradrenergic, serotoninergic, cholinergic, dopaminergic and glutaminergic neurons; influences the release of other NTM via presynaptic H3 receptors

   

   

  G) Weight reduction

  • Weight reduction means: reducing calorie intake; Consequences:
    • Lower protein intake
    • Gluconeogenesis and fatty acid production from amino acids á
    • Degradation of structural proteins (muscles, enzymes, immunoglobulins, transport albumin) à reduced performance, tiredness, exhaustion, premature “diet termination”
    • Colloid osmotic pressure decreases with edema formation and reduced diuresis (amino acids regulate water balance)
    • Important amino acids as part of a diet:
      • Neurotransmitters and precursors (e.g. tryptophan, phenylalanine, glutamine, taurine)
      • Arginine (activation of the somatotrophic hormone STH à reduces fat mass)
      • Carnitine (fat burning)

   

  H) Sport / Performance

  • Structural development (especially muscles)
  • Optimization of metabolism (e.g. immune system, redox system, psyche)
  • Energy generation (including reserve energy)
  • Antioxidant effect (high levels of radicals during extreme sports
  • Important amino acids to increase performance:
    • L-Carnitine (Energy)
    • Coenzyme Q 10 (energy)
    • Creatine (Energy)
    • Glutathione (antioxidant)
    • Essential AS, especially branched-chain AS as well as arginine, glutamine (structure structure)

   

  I) Healthy longevity (“Longevity”)

  • A good supply of amino acids is a useful building block in an overall “good aging” concept.
    • Amino acids are, among other things, building blocks of proteins and other essential substances
    • Optimization of metabolism (e.g. immune system, redox system, psyche, hormones)
    • Optimization of the supporting tissue
    • Optimization of organ functions (e.g. cardiovascular system, nerves, skin)
  • Important amino acids for “aging skin” (e.g. dryness, wrinkle formation, collagen deficiency, healing)
    • Arginine
    • Cysteine
    • Proline
    • Glycine
    • Mix of essential amino acids
    • Spermidine

   

   

   

  Symptoms of amino acid and protein deficiency

  • Swollen eyes and legs (water from blood vessels in wtjust relocated)
  • Muscles become weaker (muscle breakdown)
  • Hair becomes thinner (due to lack of keratin)
  • Nails become brittle
  • Skin becomes dry and flaky (wrinkle formation)
  • Mental alertness decreases
  • Fatigue and sleep disorders
  • Immunodeficiency (susceptibility to infections)
  • Wound healing disorders
  • Micronutrient deficit (protein transports micronutrients)
  • Blood sugar fluctuations and cravings for sweets (feeling of lack of satiety)

   

  Which amino acids should be examined for a deficiency if there are specific symptoms?

  Indication	Lead AS (mainly affected)
  Detoxification	Cysteine, glutamic acid, glycine
  Hair loss	Cysteine, methionine, tyrosine, glutathione
  Skin diseases	Arginine, cysteine, glutamine, lysine
  Heart diseases	Arginine, Lysine, Methionine, Taurine, Carnitine
  Obesity	Arginine, Methionine, Phenylalanine, Tryptophan, Tyrosine
  Gastrointestinal	Glutamine, threonine, methionine, tryptophan, glutathione
  Immune system	Lysine, methionine, arginine, tryptophan, glutamine
  Parkinson's disease	Phenylalanine, tyrosine, carnitine

  Source: Ganzimmun

   

  Examples of amino acids in food

  Methionine	Egg, whey, whole grain bread, corn, rice
  Lysine	Meat, egg, whey, soy, potato, wheat germ, lentils
  Leucine	Pumpkin seeds, oats, almonds, lentils, crispbread
  Isoleucine	Meat, cheese, pumpkin seeds, oats, almonds, lentils, soy
  Threonine	Meat, cheese, pumpkin seeds, oats, almonds, lentils, soy
  Valine	Meat, cheese, pumpkin seeds, oats, almonds, lentils, soy
  Phenylalanine	Meat, cheese, pumpkin seeds, oats, almonds, lentils, soy
  Tryptophan	Cocoa powder, buckwheat, linseed, sesame, apricot kernels, pumpkin seeds, African black bean (Griffonia simplicifolia)
  Histidine	Meat, liver, trout, tuna, cheese, lentils, sunflower seeds, lupins, soybeans
  Arginine	Meat, fish, nuts, soy, wheat germ, brown rice, oats
  Taurine	Meat, Fish
  Glutamine	Meat, fish, soy, beans
  Glycine	Beef, liver, peanuts, oats
  Carnitine	Red meat, crab
  Alanine	Beef, pork, egg white, whey, whole corn, rice, soy, oats
  Tyrosine	Cocoa powder, buckwheat, linseed, sesame, apricot kernels, pumpkin seeds

   

  Examples of foods high in essential amino acids (and arginine)

  Food (Indication in g AS per 100 g of food)	Histidine	Isoleucine *	Leucine *	Lysine	Methionine	Phenylalanine	Threonine	Tryptophan	Valine *	Arginine
  Amaranth	0.38	0.58	0.87	0.74	0.22	0.54	0.55	0.18	0.67	1.06
  Brush beans (raw)	0.29	0.24	0.50	0.62	0.09	0.68	0.23	0.03	0.29	0.39
  Oats (raw)	0.20	0.41	0.77	0.44	0.16	0.53	0.37	0.16	0.57	0.68
  Hazelnut	0.40	0.57	1,10	0.47	0.21	0.71	0.48	0.21	0.75	2.27
  Sunflower seeds	0.69	1,13	1.70	0.99	0.56	1.28	0.95	0.37	1.33	2.46
  Lentils (raw)	0.59	1,11	1.78	1.73	0.19	1.23	0.98	0.22	1.33	1.95
  Lupins	1.03	1.61	2.74	1.93	0.25	1.43	1.33	0.28	1.51	3.87
  Almond sweet	0.53	0.91	1.51	0.60	0.27	1,20	0.63	0.17	1,18	2.84
  Soybeans (ripe, raw)	1.09	1.97	3.30	2.70	0.54	2,12	1.76	0.59	2.02	3.15
  Tempeh (fermented soy)	0.48	0.91	1.47	1.06	0.23	0.89	0.68	0.17	0.89	1,12
  Tofu	0.40	0.74	1.24	0.96	0.19	0.84	0.57	0.20	0.76	1,14
  Egg	0.26	0.73	0.99	0.70	0.35	0.63	0.56	0.18	0.88	0.70
  Parmesan	0.92	1.78	2.89	2.18	0.71	1.41	1.26	0.40	1.94	1.01
  Yoghurt 1.5%	0.09	0.22	0.38	0.28	0.09	0.19	0.16	0.04	0.27	0.13
  Tuna (cooked)	0.88	0.98	1.75	1.79	0.49	0.85	0.95	0.24	1.15	1.01
  Beef (cooked)	0.49	0.75	1,22	1.27	0.37	0.62	0.67	0.16	0.82	0.91
  Recommendation/day (in g)	0.7	1,4	2.7	2,1	0.7	1.75**	1,0	0.28	1.8	1.5

   

   

  Diagnostics “essential amino acids”

  Substance	Normal values ​​(mg/dl)	Focus points
  Histidine	1.226-1.877	Hemoglobin formation, detoxification, precursor of histamine
  Lysine	2.266-4.020	Cardiovascular protection factor, immune system, building block of carnitine
  Threonine	1.429-2.239	Collagen building block, immune system, intestinal barrier
  Phenylalanine	0.760-2.973	Has an analgesic effect, precursor of tyrosine, thyroxine and catecholamines
  Tryptophan	0.694-1.838	Lowering blood pressure, promoting sleep, immune system, Precursor kynurenine, vitamin B3, serotonin and melatonin
  (Arginine)	1.307-2.439	Immune system, collagen synthesis, precursor of NO (e.g. vascular dilatation, redox system)
  Methionine	0.373-0.731	Methyl group donor, detoxification, immune system, redox system, Precursor of cysteine ​​and taurine, building block of carnitine
  Leucine Isoleucine Valine	1.377-2.637 0.708-1.377 2.226-4.100	Reserve energy Nitrogen suppliers Protein building blocks

   

  Suggestions for approximate daily requirements of essential amino acids (in g)

  Substance	Demand
  Isoleucine (VK) Leucine (VK) Lysine Methionine (SH) Phenylalanine (AAS) Threonine Tryptophan (AAS) Valine (VK) Histidine (AAS) Arginine (SE)	1.4 g 2.2 g 1.6 g 2.2 g 2.2 g 1 g 0.5 g 1.6g 0.5g 1.5g

  VK = branched-chain amino acids; SH = Sulfur-containing amino acids; AAS = Aromatic Amino Acids; SE = semi-essential

  15

  Tempeh (fermented soy)

  0.48

  0.91

  1.47

  1.06

  0.23

  0.89

  0.68

  0.17

  0.89

  1,12

  Tofu

  0.40

  0.74

  1.24

  0.96

  0.19

  0.84

  0.57

  0.20

  0.76

  1,14

  Egg

  0.26

  0.73

  0.99

  0.70

  0.35

  0.63

  0.56

  0.18

  0.88

  0.70

  Parmesan

  0.92

  1.78

  2.89

  2.18

  0.71

  1.41

  1.26

  0.40

  1.94

  1.01

  Yoghurt 1.5%

  0.09

  0.22

  0.38

  0.28

  0.09

  0.19

  0.16

  0.04

  0.27

  0.13

  Tuna (cooked)

  0.88

  0.98

  1.75

  1.79

  0.49

  0.85

  0.95

  0.24

  1.15

  1.01

  Beef (cooked)

  0.49

  0.75

  1,22

  1.27

  0.37

  0.62

  0.67

  0.16

  0.82

  0.91

  Recommendation/day (in g)

  0.7

  1,4

  2.7

  2,1

  0.7

  1.75**

  1,0

  0.28

  1.8

  1.5

   

   

  Diagnostics “essential amino acids”

  Substance	Normal values ​​(mg/dl)	Focus points
  Histidine	1.226-1.877	Hemoglobin formation, detoxification, precursor of histamine
  Lysine	2.266-4.020	Cardiovascular protection factor, immune system, building block of carnitine
  Threonine	1.429-2.239	Collagen building block, immune system, intestinal barrier
  Phenylalanine	0.760-2.973	Has an analgesic effect, precursor of tyrosine, thyroxine and catecholamines
  Tryptophan	0.694-1.838	Lowering blood pressure, promoting sleep, immune system, Precursor kynurenine, vitamin B3, serotonin and melatonin
  (Arginine)	1.307-2.439	Immune system, collagen synthesis, precursor of NO (e.g.b Vascular dilatation, redox system)
  Methionine	0.373-0.731	Methyl group donor, detoxification, immune system, redox system, Precursor of cysteine ​​and taurine, building block of carnitine
  Leucine Isoleucine Valine	1.377-2.637 0.708-1.377 2.226-4.100	Reserve energy Nitrogen suppliers Protein building blocks

   

  Suggestions for the approximate daily requirement of essential amino acids (in g)

  Substance	Demand
  Isoleucine (VK) Leucine (VK) Lysine Methionine (SH) Phenylalanine (AAS) Threonine Tryptophan (AAS) Valine (VK) Histidine (AAS) Arginine (SE)	1.4 g 2.2 g 1.6 g 2.2 g 2.2 g 1 g 0.5 g 1.6g 0.5g 1.5g

  VK = branched-chain amino acids; SH = Sulfur-containing amino acids; AAS = Aromatic Amino Acids; SE = semi-essential