Patent ID: 7820404

Claim:
A protein cleavage method for cleaving a protein to obtain an amino acid or a peptide by a protease, wherein the protein is subjected to protease treatment in the presence of a compound represented by Formula (I) below, R—X (I) where, R represents straight-chain alkyl or straight-chain acyl with a carbon number of 9 to 16, branched-chain alkyl or branched-chain acyl with a carbon number of 10 to 40 and a main-chain carbon number of 9 to 16, or straight-chain alkyl with a straight-chain carbon number of 4 to 13 that is substituted by cycloalkyl with a carbon number of 3 to 8, and X represents a sugar residue wherein the protein is subjected to the protease treatment in the presence of the compound and a nitro compound.