Ostrich (Struthio camelus) carboxypeptidase A: purification, kinetic properties and characterization of the pancreatic enzyme.
1. Carboxypeptidase A beta and carboxypeptidase A tau-type from the pancreas of the ostrich were purified by water extraction of acetone powder, aminobenzylsuccinic acid affinity and hydroxylapatite chromatography. 2. The final preparations were homogeneous when subjected to SDS-PAGE and PAGE. The M(r) values obtained from SDS-PAGE for CPA beta and CPA tau-type were 34,600 and 34,400, respectively. 3. The effects of inhibitors (1,10 phenanthroline and indole-3-acetic acid), pH and temperature on CPA activity were examined. Ki-values for CPI, PPA, D-phe, D-trp and aminobenzylsuccinic acid were determined. 4. Km, kcat and kcat/Km values were determined for hipp-phe, cbz-gly-phe, cbz-(gly)2-phe, cbz-gly-leu, cbz-(gly)2-leu and cbz-(gly)2-val. 5. N-terminal sequencing and amino acid analysis were performed for CPA beta and CPA tau-type.
Department of Biochemistry, University of Port Elizabeth, Republic of South Africa.
G
G
Bradley
R J
RJ
Naudé
K
K
Muramoto
F
F
Yamauchi
W
W
Oelofsen
D000595:Amino Acid Sequence; D000818:Animals; D001717:Birds / Q000378:metabolism*; D002268:Carboxypeptidases / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D043422:Carboxypeptidases A; D002417:Cattle; D004795:Enzyme Stability; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007210:Indoleacetic Acids / Q000494:pharmacology; D007700:Kinetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009842:Oligopeptides / Q000737:chemistry; D010179:Pancreas / Q000201:enzymology; D010618:Phenanthrolines / Q000494:pharmacology; D051381:Rats; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D013696:Temperature
D007210:Indoleacetic Acids; D009842:Oligopeptides; D010618:Phenanthrolines; C030737:indoleacetic acid; D002268:Carboxypeptidases; D043422:Carboxypeptidases A; C025205:1,10-phenanthroline