leucin

1 definition found

leucin - Collaborative International Dictionary of English v.0.48 :

  Leucine \Leu"cine\ (l[=oo]"s[=e]n), Leucin
  \Leu"cin\(l[=u]"s[i^]n), n. [Gr. leyko`s white.] (Physiol.
     Chem.)
     a naturally occurring alpha-amino acid
     ((CH3)2CH.CH2.CH(NH2)-COOH), one of the building units of
     almost all proteins of living organisms, both animal and
     vegetable. It is one of the essential amino acids (not
     synthesized by the human body, a required component for
     proper nutrition), and is hydrophobic in character when bound
     in proteins. In isolated form it is a white, crystalline,
     zwitterionic substance formed, e. g. by the decomposition of
     proteins by pancreatic digestion, by the action of boiling
     dilute mineral acid, or by putrefaction. Chemically it is to
     be considered as amido-caproic acid. It occurs as two optical
     isomers, the L- and D-forms. The L-form, L-leucine, is the
     natural form, present in most proteins.
     [1913 Webster +PJC]