Indicators
The levorotatory isomer of the aromatic amino acid tyrosine. L-tyrosine is a naturally occurring tyrosine and is synthesized in vivo from L-phenylalanine. It is considered a non-essential amino acid; however, in patients with phenylketonuria who lack phenylalanine hydroxylase and cannot convert phenylalanine into tyrosine, it is considered an essential nutrient. In vivo, tyrosine plays a role in protein synthesis and serves as a precursor for the synthesis of catecholamines, thyroxine, and melanin.
Indicators
A family of pyridoxal phosphate-dependent enzymes involved in cellular nitrogen metabolism, amino acid metabolism, and liver gluconeogenesis. Alanine aminotransferase specifically and reversibly catalyzes the transfer of an amino group from L-alanine to alpha-ketoglutarate forming pyruvate and L-glutamate.
Indicators
An essential amino acid in juvenile humans, Arginine is a complex amino acid, often found at active site in proteins and enzymes due to its amine-containing side chain. Arginine may prevent or treat heart and circulatory diseases, combat fatigue, and stimulate the immune system. It also boosts production of nitric oxide, relaxing blood vessels, and treating angina and other cardiovascular problems. Arginine is also an important intermediate in the urea cycle and in detoxification of nitrogenous wastes. (NCI04)
Indicators
A natural water-soluble vitamin (Vitamin C). Ascorbic acid is a potent reducing and antioxidant agent that functions in fighting bacterial infections, in detoxifying reactions, and in the formation of collagen in fibrous tissue, teeth, bones, connective tissue, skin, and capillaries. Found in citrus and other fruits, and in vegetables, vitamin C cannot be produced or stored by humans and must be obtained in the diet. (NCI04)
Indicators
A family of pyridoxal phosphate-dependent enzymes involved in amino acid metabolism and in the urea and tricarboxylic acid cycles. Aspartate aminotransferase specifically and reversibly catalyzes the transfer of an amino group from L-aspartate to alpha-ketoglutarate forming oxaloacetate and L-glutamate.
Indicators
A non-essential amino acid. In hepatocytes, L-citrulline is synthesized in the urea cycle by the addition of carbon dioxide and ammonia to ornithine. L-citrulline is converted into L-arginine by the enzymes argininosuccinate synthetase and argininosuccinate lyase in the presence of L-aspartate and ATP. Subsequently, L-arginine is converted to nitric oxide by nitric oxide synthase and L-citrulline is regenerated as a by-product.
Indicators
Not considered one of the 20 amino acids, Cystine is a sulfur-containing derivative obtained from oxidation of cysteine amino acid thiol side chains. It functions as an antioxidant and protects tissues against radiation and pollution, slowing the aging process. It also aids protein synthesis. Cystine is abundant in many proteins of skeletal tissues and skin, and found in insulin and digestive enzymes chromotrypsinogen A, papain, and trypsinogen. (NCI04)
Indicators
This gene is involved in the mediation of protein ubiquitination.
Indicators
A collective term for pteroylglutamic acids and their oligoglutamic acid conjugates. As a natural water-soluble substance, folic acid is involved in carbon transfer reactions of amino acid metabolism, in addition to purine and pyrimidine synthesis, and is essential for hematopoiesis and red blood cell production. (NCI05)
Indicators
Galectin-3 (250 aa, ~26 kDa) is encoded by the human LGALS3 gene. This protein plays a role in both antibody-mediated immunity and carbohydrate binding.
Indicators
A non-essential alpha-amino acid and excitatory neurotransmitter. Glutamic acid can serve as a precursor for the synthesis of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA).
Indicators
A nonessential amino acid. Glutamine can donate the ammonia on its side chain to the formation of urea (for eventual excretion by the kidneys) and to purines (necessary for the synthesis of nucleic acids). Glutamic acid-to-glutamine conversion, in which an ammonia group is added to glutamic acid (catalyzed by glutamine synthase), is of central importance in the regulation of toxic levels of ammonia in the body. This agent is a substrate for the production of both excitatory and inhibitory neurotransmitters (glutamate and GABA) and is also an important source of energy for the nervous system. Glutamine may become a conditionally essential amino acid during certain catabolic states.
