Activation of proPHBSP, the Zymogen of a Plasma Hyaluronan Binding Serine Protease, by an Intermolecular Autocatalytic Mechanism
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Michael Etscheid
Abstract
The hyaluronic acid binding serine protease (PHBSP), an enzyme with the ability to activate the coagulation factor FVII and the plasminogen activator precursors and to inactivate factor VIII and factor V, could be isolated from human plasma in the presence of 6m urea as a single-chain zymogen, whereas under native conditions only its activated two-chain form was obtained. The total yield of proenzyme (proPHBSP) was 5–6 mg/l, corresponding to a concentration of at least 80–100nm in plasma. Upon removal of urea, even in the absence of charged surfaces a rapid development of amidolytic activity was observed that correlated with the appearance of the two-chain enzyme. The highest activation rate was observed at pH 6. ProPHBSP processing was concentration-dependent following a second order kinetic and was accelerated by catalytic amounts of active PHBSP, indicating an intermolecular autocatalytic activation. Charged macromolecules like poly-L-lysine, heparin, and dextran sulfate strongly accelerated the autoactivation, suggesting that in vivo proPHBSP activation might be a surface-bound process. The intrinsic activity of the proenzyme was determined to be 0.25–0.3%, most likely due to traces of PHBSP. The presence of physiological concentrations of known plasma inhibitors of PHBSP, like α2 antiplasmin and C1 esterase inhibitor, but not antithrombin III/heparin, slowed down zymogen processing. Our in vitro data suggest that the autoactivation of proPHBSP during plasma fractionation is induced by the removal of inhibitors of PHBSP and is accelerated by charged surfaces of the chromatographic resins.
Copyright © 2000 by Walter de Gruyter GmbH & Co. KG
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- Activation of proPHBSP, the Zymogen of a Plasma Hyaluronan Binding Serine Protease, by an Intermolecular Autocatalytic Mechanism
- Human and Rat Dipeptidyl Peptidase III: Biochemical and Mass Spectrometric Arguments for Similarities and Differences
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- Erratum: The following abstract was unfortunately omitted from the GBM Fall Meeting section of the Biological Chemistry Special Supplement, Vol. 381, September 2000
- Content Index
- Author Index
- Subject Index
Articles in the same Issue
- Circadian Rhythms of Sterol 12α-Hydroxylase, Cholesterol 7α-Hydroxylase and DBP Involved in Rat Cholesterol Catabolism
- Mannosidase Action, Independent of Glucose Trimming, Is Essential for Proteasome-Mediated Degradation of Unassembled Glycosylated Ig Light Chains
- Characterization of a Receptor for Heat Shock Protein 70 on Macrophages and Monocytes
- Yeast Translational Activator Cbs2p: Mitochondrial Targeting and Effect of Overexpression
- Mutational Scanning of a Hairpin Loop in the Tryptophan Synthase β-Subunit Implicated in Allostery and Substrate Channeling
- The Difference in the Carboxy-Terminal Sequence Is Responsible for the Difference in the Activity of Chicken and Rat Liver Fructose-2,6-Bisphosphatase
- Crystal Structure of the Caspase Activator Human Granzyme B, a Proteinase Highly Specific for an Asp-P1 Residue
- Primary Structure of Potato Kunitz-Type Serine Proteinase Inhibitor
- Activation of proPHBSP, the Zymogen of a Plasma Hyaluronan Binding Serine Protease, by an Intermolecular Autocatalytic Mechanism
- Human and Rat Dipeptidyl Peptidase III: Biochemical and Mass Spectrometric Arguments for Similarities and Differences
- Recombinant Anti-Stefin A Fab Fragment: Sequence Analysis of the Variable Region and Expression in Escherichia coli
- Green Fluorescent Protein Photobleaching: a Model for Protein Damage by Endogenous and Exogenous Singlet Oxygen
- 193 nm Photolysis of Aromatic and Aliphatic Dipeptides in Aqueous Solution: Dependence of Decomposition Quantum Yield on the Amino Acid Sequence
- NADPH:Protochlorophyllide Oxidoreductase Uses the General Import Route into Chloroplasts
- Superoxide Reactivates Nitric Oxide-Inhibited Catalase
- Erratum: The following abstract was unfortunately omitted from the GBM Fall Meeting section of the Biological Chemistry Special Supplement, Vol. 381, September 2000
- Content Index
- Author Index
- Subject Index
