... AJI92,USP26,EP4,USP29 L-LeucineIndications and UsageLeucine (abbreviated as Leu or L) is a branched-chain α-amino acid with the chemical formula ... HO2CCH(NH2)CH2CH(CH3)2. It is an essential amino acid, which ... ferritin, astacin and other 'buffer' proteins. As an essential amino acid, leucine is not synthesized in animals, hence it must be ...