Human Carbonic Anhydrases: X. PREPARATION OF LARGE PEPTIDE FRAGMENTS OF CARBONIC ANHYDRASE B USED FOR SEQUENCE STUDIES

Abstract

Abstract Human carbonic anhydrase B was converted into large peptides for use in sequence analysis by cleaving the molecule with cyanogen bromide at the methionine residues and by tryptic digestion. A relatively large amount of insoluble tryptic digestion products was obtained which consisted of partially hydrolyzed peptides. Some were soluble in guanidine HCl and could be fractionated by gel filtration to give a series of large overlapping peptides useful in sequence analyses. A linear model of the enzyme has been constructed which shows the positions of residues cleaved to provide these peptides.