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Updated: Jul 5, 2026

Evaluation of Protein–Protein Interactions using an On-Membrane Digestion Technique
Published on: July 19, 2019
Chemical cleavage of proteins in solution
Dan L Crimmins1, Sheenah M Mische2, Nancy D Denslow3
1Washington University School of Medicine, St. Louis, Missouri.
Abstract:
Described in this unit are five basic protocols that are widely used for specific and efficient chemical cleavage of proteins in solution. Cyanogen bromide (CNBr) cleaves at methionine (Met) residues; BNPS-skatole cleaves at tryptophan (Trp) residues; formic acid cleaves at aspartic acid-proline (Asp-Pro) peptide bonds; hydroxylamine cleaves at asparagine-glycine (Asn-Gly) peptide bonds, and 2-nitro-5-thiocyanobenzoic acid (NTCB) cleaves at cysteine (Cys) residues. Because the above loci are at relatively low abundance in most proteins, digestion with these agents will yield relatively long peptides.
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