Interaction between thrombin mutant W215A/E217A and direct thrombin inhibitor
Year: 2008
Type: article
Abstract: Thrombin mutant W215A/E217A acts as an anticoagulant when administered intravenously by activating plasma protein C in concert with endothelial thrombomodulin [1,2]. The double mutation in the catalytic domain of the W215A/E217A molecule leads to compromised interactions with fibrinogen and chromogenic thrombin substrates [1,3]. Among direct thrombin inhibitors (DTIs), argatroban exerts antithrombotic activity by a rapid binding to the catalytic domain of thrombin, while lepirudin and bivalirudin occupy both exosite I and catalytic domains [4]. We hereby report on the changes in DTI-interaction with W215A/ E217A, using thrombin substrate hydrolysis [1,3], activated partial thromboplastin time (aPTT) and the Thrombinoscope methods (Thrombinoscope BV, Maastricht, Netherlands) [5]. Based on the inhibition of H-D-Phe-Pro-Arg-p-nitroanilide hydrolysis, argatroban and lepirudin interact with the catalytic domain of W215A/E217A with a 7000-fold reduced affinity relative to wild-type thrombin (Table 1) [6]. This reduction coincides with the 19 000-fold decrease in affinity for fibrinogen [1]. On the contrary, lack of inhibition of the substrate hydrolysis with bivalirudin suggests that W215A/E217A binds to bivalirudin utilizing exosite I without blocking the active site. This finding was confirmed in studies looking at the
Source: Blood Coagulation & Fibrinolysis
Language: English
Subfield: Hematology
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2079144460