Reaction of thrombins with human antithrombin III: II. Dependence of rate of inhibition on molecular form and origin of thrombin

Thrombosis Research
Z S Latallo, C M Jackson

Abstract

The rate of thrombin inhibition by AT III depends upon the molecular form (alpha, beta, gamma) and species origin of the enzyme. The following apparent second order rate constants (.1000/M.s) were established alpha human 11.24 +/- 0.8; alpha bovine 7.46 +/- 0.27; beta bovine 6.49 +/- 0.34 and gamma human thrombin 2.80 +/- 0.11, 25 degrees C, pH = 7.80, 0.01 M TRIS, 0.01 M HEPES buffer, 0.0025 M EDTA, 0.3 M NaCl, 1 mg/mL PEG 6000. Using these values, the concentration of active AT III in an unknown sample can be calculated from the measured apparent first order rate constant in moles/liter instead of relative units. In contrast to the reactions in the absence of heparin, in the presence of high affinity heparin, the differences between various forms of thrombin are more pronounced and the shape of the progress curves, as well as rates, are highly dependent on the ionic strength. In the presence of heparin, measurement of the rate of inhibition under pseudo first order conditions can be made only when the NaCl concentration is at least 0.3 M. The significance of the presented data for designing a functional assay of AT III is discussed.

References

Aug 15, 1977·European Journal of Biochemistry·B NordenmanI Björk
Jan 9, 1979·Biochemistry·T ChangJ W Fenton
Apr 13, 1979·Biochemical and Biophysical Research Communications·M J GriffithR L Lundblad
Oct 29, 1982·Molecular and Cellular Biochemistry·I Björk, U Lindahl

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Citations

May 1, 1989·Proceedings of the National Academy of Sciences of the United States of America·P J Hogg, C M Jackson
Jan 6, 2004·Medicinal Research Reviews·Umesh R Desai
Oct 1, 1991·APMIS : Acta Pathologica, Microbiologica, Et Immunologica Scandinavica·A M Bergholm, K Dornbusch
Apr 27, 2017·Biophysical Journal·Laura M HaynesKathleen E Brummel-Ziedins

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