[Specific cleavage of the cysteine-peptide bond of thermitase].

: Cyanylation and N-cysteine peptide bond cleavage of thermitase using 2-nitro-5-thiocyanobenzoic acid results in the formation of two peptide fragments (mol. wt. 20 000 and 10 000) in high yield (about 90%). These peptides are well separated by gel filtration on Sephadex G-75 in the preparative scale.