|
|
||||||||
Clinical Chemistry, Vol 32, 934-937, Copyright © 1986 by American Association for Clinical Chemistry
SA Sonder and JW Fenton 2d
To assess the thrombin specificity of tripeptide chromogenic substrates, we determined the Michaelis--Menten (Km), catalytic (kcat), and specificity (kcat/Km) constants for S-2238 (H-D-Phe-Pip-Arg-p- nitroanilide), Chromozym-TH (Tos-Gly-Pro-Arg-p-nitroanilide), and Spectrozyme-TH (H-D-hexahydrotyrosyl-Ala-Arg-p-nitroanilide) with high- purity thrombin preparations. Human and bovine alpha-thrombins, prepared by essentially the same procedure, were each greater than 95% in the form of the enzyme (alpha-thrombin) and had a specific fibrinogen-clotting activity greater than 2000 kilo-clotting units per gram of protein (kcu/g). In contrast, human gamma- and bovine beta- thrombins, made by controlled passage of alpha-thrombin through trypsin agarose, were greater than 98% of their respective forms and had fibrinogen-clotting activity less than 1 kcu/g. With the tripeptide chromogenic substrates these four thrombin forms at pH 7.8 and 23 degrees C had Km values of 1.6 to 16 mol/L, kcat values of 35 to 130 s- 1, and kcat/Km ratios of 4.7 to 52 L X mol-1 X s-1. Although Km for an individual substrate was slightly higher for bovine than for human alpha-thrombins and although Km values for the nonclotting forms (human gamma- and bovine beta-thrombins) were higher than for clotting forms (alpha-thrombins), we found no major differences among the kinetic values for the three substrates.
The following articles in journals at HighWire Press have cited this article:
![]() |
B. L. Henry, B. H. Monien, P. E. Bock, and U. R. Desai A Novel Allosteric Pathway of Thrombin Inhibition: EXOSITE II MEDIATED POTENT INHIBITION OF THROMBIN BY CHEMO-ENZYMATIC, SULFATED DEHYDROPOLYMERS OF 4-HYDROXYCINNAMIC ACIDS J. Biol. Chem., November 2, 2007; 282(44): 31891 - 31899. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Kanazawa and T. Yoshikawa Up-Regulation of Thrombin Activity Induced by Vascular Endothelial Growth Factor in Asthmatic Airways Chest, October 1, 2007; 132(4): 1169 - 1174. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Terada, E. A. B. Kelly, and N. N. Jarjour Increased Thrombin Activity after Allergen Challenge: A Potential Link to Airway Remodeling? Am. J. Respir. Crit. Care Med., February 1, 2004; 169(3): 373 - 377. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |