Methanolysis of the pyrrolidone ring of amino-terminal pyroglutamic acid in model peptides

✍ Scribed by Ichiro Kawasaki; Harvey A. Itano

• Book ID: 102982036
• Publisher: Elsevier Science
• Year: 1972
• Tongue: English
• Weight: 653 KB
• Volume: 48
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(72)90110-8

✦ Synopsis

Several useful procedures in the amino acid sequence analysis of polypeptides depend upon chemical reactions of the terminal a-amino group. Blockage of this group because of an amino-terminal pyroglutamyl residue is, therefore, a severe hindrance to the structural study of a polypeptide or protein. Methods for producing a free a-amino group on a peptide with an amino-terminal pyroglutamic acid include alkaline hydrolysis of the pyroglut.amyl to a glutamyl residue (1) , exposure of the a-amino group of the adjacent residue by enzyme-catalyzed hydrolytic removal of the pyroglutamyl residue (a), and reductive conversion of the pyroglutamyl to a prolyl residue (3). In the present, work the y-methyl ester of glutamic acid is produced at the amino terminus of peptides by methanolysis of the pyrrolidone ring of pyroglutamic acid.

MATERIALS AND METHODS3