/luy"seen, -sin/, n. Biochem.a crystalline, basic, amino acid, H2N(CH2)4CH(NH2)COOH, produced chiefly from many proteins by hydrolysis, essential in the nutrition of humans and animals. Abbr.: Lys; Symbol: K[1890-95; LYS- + -INE2]
* * *One of the essential amino acids, present in many common proteins.Its proportion in the proteins of some important food plants (including wheat and corn) is so small that populations dependent on these grains as the sole source of dietary protein suffer from lysine deficiency, affecting growth in children and general well-being in adults. It is used in biochemical and nutritional research, in pharmaceuticals, in fortified foods, and as a nutritional supplement and feed additive.
* * *an amino acid released in the hydrolysis of many common proteins but present in small amounts or lacking in certain plant proteins; e.g., gliadin from wheat, zein from corn (maize). First isolated from casein (1889), lysine is one of several so-called essential amino acids for warm-blooded animals; i.e., they cannot synthesize it and require dietary sources. (It is formed in plants, algae, and fungi by two distinct biosynthetic pathways.) Human populations dependent on grains as a sole source of dietary protein suffer from lysine deficiency.
* * *