Aggregate Formation of Peptic Globin Digest.

Peptic globin digest (PG) was prepared from porcine blood globin, and the peptides were characterized by separation processes such as gel filtration chromatography, hydrophobic chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Aggregation of the peptides was indicated by highperformance liquid chrornatography (HPLC). Two fractions (FI and F2) were obtained from PG by gel filtration chromatography. Hydrophobic chromatography of fraction F1 was carried out, and a peak corresponding to the aggregate was found in fractions Flb-Fle. These fractions, which showed an aggregate peak by HPLC, were subjected to SDS-PAGE, and two major peptide bands with molecular weight of 5000 and 6000 were found. Amino acid sequence indicated the N-terminal amino acid of these peptides to be 42-47 (Phe-Asp) and 86-92 (Ala-Leu) of p-globin, respectively. Furthermore, it was predicted that the Mw 5000 and 6000 peptides may possibly be 42-85 (MW 4749) and 86-141 (MW 6117) of p-globin, respectively, based on the specificity of pepsin.