title: Proteins of hepatitis B surface antigen.
abstract: Purified 22-nm forms of hepatitis B surface antigen (Hbsag) representing the three major antigenic subtypes (adw, ayw, and adr) were analyzed for their constituent polypeptides by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. No consistent difference in either the number or relative distributions of the polypeptides was observed for the various subtypes. Seven polypeptides were designated as P-1 through P-7 in order of their decreasing mobilities. By comparison with protein standards, their molecular weights were estimated as 23, 29.5, 36, 41.5, 53.5, 72, and 97 thousand. The P-1 and P-2 components represented the major polypeptides; P-2 and P-5 might by glycoproteins, based on their reaction with periodic acid-Shiff reagent. Each polypeptide contains cysteine residues. HBSAg was radiolabeled with 3H or 14C by reductive methylation or iodinated with 125I by the chloramine-T or lactoperoxidase procedures. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of labeled HBSAg yielded patterns identical to those obtained with protein stain. Comparison of HBSAg labeled by the chloramine-T and lactoperoxide procedures indicated that there was no distinction between internal or external components within the 22-nm structure.
mesh_terms: D003545:Cysteine / Q000032:analysis; D006023:Glycoproteins / Q000032:analysis; D006514:Hepatitis B Surface Antigens / Q000032:analysis*; D006801:Humans; D008970:Molecular Weight; D010455:Peptides / Q000032:analysis; D010949:Plasma / Q000382:microbiology; D014764:Viral Proteins / Q000032:analysis*
chemical_list: D006023:Glycoproteins; D006514:Hepatitis B Surface Antigens; D010455:Peptides; D014764:Viral Proteins; D003545:Cysteine