Primary structure of 3-phosphoglycerate kinase from horse muscle. I. Purification of cyanogen bromide peptides and amino acid sequence of peptide CB5 (104 residues).

3-Phosphoglycerate kinase was isolated from horse muscle and subjected to the action of cyanogen bromide. The resulting peptides were separated using gel filtration combined with either ion exchange chromatography on phosphocellulose in 6 M urea or high voltage paper electrophoresis. The sequence of the largest peptide, CB5, has been determined by a combination of automated and manual Edman degradation carried out on the intact peptide and derivatives obtained by proteolytic digestion. The isolation of two peptides derived from CB5 by cleavage of the bond between Asp109 and Pro110 facilitated the sequence analysis of CB5. The sequence analysis of the remaining 13 cyanogen bromide fragments and the complete sequence of the enzyme are described in the second paper of this series (Merrett, M. (1981), J. Biol. Chem. 256, 10293-10305).