title: Chemical studies on protease A of Bitis arietans (puff adder) venom.
abstract: Protease A of Bitis arietans venom is probably a metalloprotease, since it is inhibited by o-phenanthroline and contains 0.77 moles of zinc per mole protein. The enzyme comprises 213 amino acids, including 9 methionine residues and one free sulphydryl group. It contains one polypeptide chain, which is terminated at the carboxyl end by serine. The amino terminal sequence of protease A is: Arg-Ser-Ser-Asp-Pro-Asn-Lys-Tyr-Phe-Asn-Val-Ile-Val-Val-Val-Asp-Asn-Arg- Met-Val-Asn-Tyr-Tyr-Lys-Gly-Glu-Leu-Asn-Lys-Ile-Thr-. Despite difficulties with 'insoluble peptide core' formation, a number of peptides were purified from peptic and tryptic digests of S-derivatized protease A.
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D016282:Aspartic Acid Endopeptidases; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D010450:Endopeptidases / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D010084:Oxidation-Reduction; D010455:Peptides / Q000032:analysis; D014357:Trypsin; D014757:Viper Venoms / Q000032:analysis*
chemical_list: D000596:Amino Acids; D010455:Peptides; D014757:Viper Venoms; D010450:Endopeptidases; D014357:Trypsin; C022325:aspartic proteinase A; D016282:Aspartic Acid Endopeptidases