Characterization of a chymotrypsin-like hydrolytic activity in the opossum kidney cell.
To characterize a chymotrypsin-like hydrolytic activity in the cell surface membranes of intact opossum kidney (OK) cells, we partially purified a protease from the membrane fractions of OK cells using Suc-Leu-Leu-Val-Tyr-MCA (Suc, succinyl; MCA, 4-methylcoumaryl-7-amide), a synthetic substrate for chymotrypsin, as the substrate. The semipure enzyme showed seryl chymotrypsin-like characteristics such as preferential hydrolysis of Suc-Leu-Leu-Val-Tyr-MCA and inhibition by phenylmethylsulfonyl fluoride, diisopropylfluorophosphate, and chymostatin. However, it clearly differed from alpha-chymotrypsin in its weak ability to hydrolyze Suc-Ala-Ala-Pro-Phe-MCA and in its high molecular mass (250-300 kDa). The enzyme also had an endopeptidase-like activity in that it cleaved human parathyroid hormone(1-84) at the Leu(37)-Gly(38) and Arg(52)-Lys(53) bonds. These results suggest that a high molecular mass chymotrypsin-like endopeptidase with unique characters is present in the membrane fractions of OK cells.
Arao
M
M
Department of Medicine, Kobe University School of Medicine, Japan.
Yamaguchi
T
T
Sugimoto
T
T
Fukase
M
M
Chihara
K
K
D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000201:enzymology; D002851:Chromatography, High Pressure Liquid; D002918:Chymotrypsin / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D010450:Endopeptidases / Q000737:chemistry / Q000378:metabolism; D006868:Hydrolysis; D007668:Kidney / Q000201:enzymology*; D007700:Kinetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009842:Oligopeptides / Q000378:metabolism; D009893:Opossums; D010446:Peptide Fragments / Q000737:chemistry; D013379:Substrate Specificity
D009842:Oligopeptides; D010446:Peptide Fragments; D010450:Endopeptidases; D002918:Chymotrypsin