Anticoagulant effect of Naja naja venom 5′nucleotidase:: Demonstration through the use of novel specific inhibitor, vanillic acid
Anticoagulant effect of Naja naja venom 5′nucleotidase:: Demonstration through the use of novel specific inhibitor, vanillic acid
复制标题
DOI：
10.1016/j.toxicon.2006.06.017
复制
发表时间：
2006-09-15
期刊：
影响因子：
2.8
通讯作者：
D'Souza, Cletus J. M.
中科院分区：
文献类型：
--
作者：
Dhananjaya, B. L.;Nataraju, A.;D'Souza, Cletus J. M.
蛇毒蛋白通过促进/延迟血液凝固来影响止血。除了蛋白酶和磷脂酶A（2）s（PLA（2）s）之外，已知5 '核苷酸酶通过抑制血小板聚集来影响止血。在这项研究中，眼镜蛇毒5 '核苷酸酶可能参与介导的抗凝作用进行了评估。香草酸选择性地和特异性地抑制了N.眼镜蛇毒液。它是一种竞争性抑制剂，在底物浓度增加时抑制作用明显减轻。香草酸剂量依赖性地抑制N.眼镜蛇毒液高达40%。伴刀豆球蛋白-A（Con-A）抑制研究证实了5 '核苷酸酶部分参与介导抗凝作用。Con-A竞争性抑制体外蛋白酶和5 '核苷酸酶活性达100%。但对PLA（2）无抑制作用。Con-A对抗凝作用的抑制作用随抗凝时间的延长而逐渐减弱，提示5 ′核苷酸酶和蛋白酶都参与了N.眼镜蛇毒液。香草酸和Con-A抑制研究表明，5 '核苷酸酶可能与凝血内源性途径中的一个或多个因子相互作用而产生抗凝作用。因此，本研究首次证明了5 '核苷酸酶参与介导N。眼镜蛇毒抗凝作用。(c)2006爱思唯尔有限公司保留所有权利。
The snake venom proteins affect hemostasis by either advancing/delaying blood coagulation. Apart from proteases and phospholipase A(2)s (PLA(2)s), 5'nucleotidase is known to affect hemostasis by inhibiting platelet aggregation. In this study, the possible involvement of Naja naja venom 5'nucleotidase in mediating anticoagulant affect is evaluated. Vanillic acid selectively and specifically inhibited 5'nucleotidase activity among other enzymes present in N. naja venom. It is a competitive inhibitor as evident of inhibition relieving upon increased substrate concentration. Vanillic acid dose dependently inhibited the anticoagulant effect of N. naja venom up to 40%. This partial involvement of 5'nucleotidase in mediating anticoagulant effect is substantiated by concanavalin-A (Con-A) inhibition studies. Con-A, competitively inhibited in vitro protease and 5'nucleotidase activity up to 100%. However, it did not exhibit inhibitory activity on PLA(2). The complete inhibition of anticoagulant effect by Con-A upon recalcification time suggests the participation of both 5'nucleotidase and protease in mediating anticoagulant effect of N. naja venom. Vanillic acid and Con-A inhibition studies together suggest that probably 5'nucleotidase interacts with one or more factors of intrinsic pathway of blood coagulation to bring about anticoagulant effect. Thus, this study for the first time demonstrates the involvement of 5'nucleotidase in mediating N. naja venom anticoagulant effect. (c) 2006 Elsevier Ltd. All rights reserved.