ISOLATION AND CHARACTERIZATION OF SOME FRAGMENTS OBTAINED AFTER PEPTIC DIGESTION OF BOVINE SERUM ALBUMIN

Abstract

Bovine serum albumin was hydrolysed by pepsin at pH 3.7. Ten well‐defined fragments were found, as was shown by electrophoresis on polyacrylamide gels at pH 3.0 in the presence of 6 M urea. Three of the fragments could be isolated by precipitation with trichloroacetic acid followed by ion exchange chromatography. The procedure is suited to obtain large quantities in a simple and reproducible way. The fragments were identified by polyacrylamide gel electrophoresis, terminal amino acid determination, and amino acid analysis. The largest of the three fragments appeared to be composed of the two other fragments and is probably placed C‐terminal in albumin. Some other properties of the largest fragment were also determined, e.g., the α‐helix content and the number of titratable residues.