Tyrosinein

Tyrosinein is not a recognized chemical name in standard biochemical nomenclature. The term does not correspond to a distinct, well-established compound in major databases. It may reflect a typographical error or a confusion with related terms such as tyrosine, tyrosinase, tyrosinate, or tyrosine kinase.

If the intended subject is tyrosine, the amino acid also known as L-tyrosine, it is categorized as an aromatic amino acid. In humans it is non-essential, because phenylalanine can be converted to tyrosine; under certain metabolic conditions tyrosine becomes conditionally essential.

Biological roles: Tyrosine serves as a precursor for several important molecules, including catecholamines (dopamine, norepinephrine, epinephrine) and the pigment melanin. It is incorporated into proteins and participates in signaling via phosphorylation of tyrosine residues by tyrosine kinases.

Metabolism and synthesis: Tyrosine is synthesized from phenylalanine by phenylalanine hydroxylase. Its catabolism proceeds through transamination to p-hydroxyphenylpyruvate and further to fumarate and acetoacetate, feeding energy metabolism. Deficiencies in related enzymes can lead to metabolic disorders such as tyrosinemia.

Dietary sources and notes: Tyrosine is found in dairy products, meat, fish, eggs, soy, and legumes. Intake varies with diet; in phenylketonuria, phenylalanine restriction increases the relative importance of tyrosine. See also tyrosine kinase, tyrosinase, and tyrosinate for related terms.