ABSTRACT
Elucidation of the covalent structure of a protein requires the development of specific, reproducible methods for cleavage of the protein into fragments of a size amenable to structural analysis. Proteolytic enzymes such as trypsin, chymotrypsin, and pepsin have proven quite useful in the cleavage of specific peptide bonds in proteins. In addition to the use of specific proteases, the nature of certain amino acid residues has permitted the development of nonenzymatic chemical methods for the cleavage of certain peptide bonds.
