Leucine

Leucine (abbreviated Leu or L) is one of the twenty amino acids that cells use to synthesize proteins. It is encoded in the messenger RNA as UUA, UUG, CUU, CUC, CUA, or CUG. Its side chain is nonpolar, an isobutyl (2-methylpropyl) group. It is one of the essential amino acids. As a dietary supplement, leucine has been found to reduce the breakdown of muscle tissue by increasing muscle protein synthesis in aged rats. Leucine is used in liver, adipose tissue, and muscle tissue. In adipose and muscle tissue, it is used for sterol formation, and use in these two tissues alone is about seven times greater than use in the liver.

Properties

• Formula: C6H13NO2
• Denomination of IUPAC: Leucine
• Cruising mass: 131.17 g/mol

History

In 1819, the French pharmacist and chemist Joseph Louis Proust succeeded in isolating two substances based on wheat flour, which he called "caseic acid" and "caseous oxide". A year later, Henri Braconnot isolated a new substance, apparently by acid hydrolysis of muscle fiber and wool, and named it after the white color of the crystals "Leuicin". Eduard Mulder recognized in 1839 the identity of the two bodies and discussed its possible composition. But it was not until 1891 that the German chemist Ernst Schulze and his doctoral student Arthur Likiernik succeeded in properly constituting L-leucine.