title: Preparation and analysis of peptide fragments produced by pepsin hydrolysis of human plasma albumin and their relationship to its structure.
abstract: Human plasma albumin was prepared and subjected to proteolysis by pepsin at pH2.45 at 25 degrees for 10min. with albumin/pepsin ratio 3000:1. Five peptide fragments were detected in the proteolysate by means of zone electrophoresis and gel filtration; these were separated and purified. Molecular weights, amino acid composition and disulphide bond content of the purified fragments were determined. The results show that a high proportion of the polypeptide chain of albumin appears to have a low cystine content, and at low pH values the molecule would be expected to have a considerable degree of freedom in its structure in these regions of the chain. A tripartite model for the structure of plasma albumin is proposed.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D055598:Chemical Phenomena; D002621:Chemistry; D002850:Chromatography, Gel; D003720:Densitometry; D004586:Electrophoresis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007122:Immunoelectrophoresis; D008970:Molecular Weight; D010434:Pepsin A; D010455:Peptides / Q000032:analysis*; D011048:Polarography; D012709:Serum Albumin; D013438:Sulfhydryl Compounds / Q000032:analysis
chemical_list: D000596:Amino Acids; D010455:Peptides; D012709:Serum Albumin; D013438:Sulfhydryl Compounds; D010434:Pepsin A