Purification and properties of a human placental post-proline endopeptidase.
Post-proline endopeptidase (EC 3.4.21.26) was found in human placenta, purified 3,390-fold and characterized. The post-proline endopeptidase was able to be completely separated from dipeptidyl peptidase IV (EC 3.4.14.5) by hydrophobic phenyl Sepharose chromatography. The pH optimum of the enzyme was 6.7. The Km value for 7-(succinyl-Gly-Pro)-4-methylcumarineamide was 1.0mM. The molecular weight of this enzyme was estimated to be 140,000 by gel filtration and 67,000 by sodium dodecyl sulfate gel electrophoresis, indicating its dimetric structure. Human placental post-proline endopeptidase appeared to be a thiol protease in view of the results of inhibition studies.
D002845:Chromatography; D003593:Cytoplasm / Q000201:enzymology; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases / Q000302:isolation & purification*; D005260:Female; D006801:Humans; D008970:Molecular Weight; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy; D000085822:Prolyl Oligopeptidases; D012697:Serine Endopeptidases
D010450:Endopeptidases; D012697:Serine Endopeptidases; C000705287:PREPL protein, human; D000085822:Prolyl Oligopeptidases