Regulation of cystatin C activity by serine proteinases.
The effect of four human serine proteinases on the human cysteine proteinase inhibitor, cystatin C, has been studied in vitro. Neutrophil elastase in catalytic amounts was observed to rapidly cleave cystatin C at neutral pH, thereby giving rise to a modified form of the inhibitor lacking the N-terminal Ser1-Val10 decapeptide. The two other leukocyte serine proteinases, cathepsin G and neutrophil proteinase 4, did not catalytically hydrolyse cystatin C bonds. Neither had the seminal plasma serine proteinase, prostate-specific antigen, any effect on cystatin C. The physiological implications of neutrophil elastase catalysed modification of cystatin C are discussed, and recent findings indicating that this reaction also occurs in vivo are reviewed.
Abrahamson
M
M
Department of Clinical Chemistry, University Hospital, Lund, Sweden.
Buttle
D J
DJ
Mason
R W
RW
Hansson
H
H
Grubb
A
A
Lilja
H
H
Ohlsson
K
K
D000595:Amino Acid Sequence; D056649:Cathepsin G; D002403:Cathepsins / Q000494:pharmacology; D055316:Cystatin C; D015891:Cystatins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D053146:Myeloblastin; D009504:Neutrophils / Q000201:enzymology; D009842:Oligopeptides / Q000737:chemistry; D010196:Pancreatic Elastase / Q000494:pharmacology; D012697:Serine Endopeptidases / Q000494:pharmacology*; D013379:Substrate Specificity
C525030:CST3 protein, human; D055316:Cystatin C; D015891:Cystatins; D009842:Oligopeptides; D002403:Cathepsins; D012697:Serine Endopeptidases; C534094:CTSG protein, human; D056649:Cathepsin G; D010196:Pancreatic Elastase; D053146:Myeloblastin