Selective Cleavage and Modification of Peptides and Proteins

Abstract

Publisher Summary This chapter focuses on the different aspects of selective cleavage and modification of peptides and proteins. The selective chemical cleavages of proteins or peptides currently in use are classified into three main groups based upon the site of cleavage relative to the chemically modified residue: (1) cleavage at the α-carbon atom, (2) cleavage at the amino peptide bond, or (3) cleavage at the carboxyl peptide bond. The theme of participation of neighboring groups for peptide cleavage has stimulated numerous variations, and the search for new oxidants, alkylating reagents, and nucleophiles is still going on. Interest is almost equally divided between the dual aspects of most of these reactions; in addition to cleavage procedures, the need for selective modification of proteins continues. In addition, the knowledge of the complete tertiary structure of important enzymes, such as lysozyme, ribonuclease, α-chymotrypsin, and carboxypeptidase, has permitted a sober evaluation of the limitations of the so-called “group-specific reagents” in protein chemistry and has shown the extent of difficulty in finding an easy correlation between chemical reactivity and tertiary structure.