Factor Xa (FXa) inhibitor from the nymphs of the camel tick Hyalomma dromedarii
Factor Xa (FXa) inhibitor from the nymphs of the camel tick Hyalomma dromedarii
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DOI：
10.1016/s1096-4959(01)00459-6
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发表时间：
2001-12-01
影响因子：
2.2
通讯作者：
Khalil, MI
中科院分区：
文献类型：
--
作者：
Ibrahim, MA;Ghazy, AHM;Khalil, MI
An inhibitor of factor Xa (FXa) was isolated from the nymphs of the camel tick Hyalomma dromedarii by a combination of chromatography on DEAE-cellulose and Sephacryl S-300 columns. The isolated nymphal FXa inhibitor turned out to be a homogenous preparation of a single polypeptide chain (15 kDa) as judged by both the native and denatured SDS-PAGE. Its pI value ranged from 7.7 to 7.9. The inhibitor is a potent anticoagulant since it prolonged both the activated partial thromboplastin time (APTT) and the prothrombin time (PT) of the camel plasma in a concentration-dependent manner. Its activity was threefold lower toward thrombin than FXa, but it did not inhibit any of the proteases; trypsin, alpha -chymotrypsin, papain, pepsin and subtilisin. The inhibitor binds at two sites on FXa uncompetitively with an inhibition constant (K-1) value of 134 nM. (C) 2001 Elsevier Science Inc. All rights reserved.
