Sreedhar Roopesh, Tiku Purnima Kaul
Department of Protein Chemistry and Technology, CSIR-Central Food Technological Research Institute, Mysuru, Karnataka 570020 India.
Indian J Hematol Blood Transfus. 2018 Apr;34(2):314-321. doi: 10.1007/s12288-017-0856-2. Epub 2017 Aug 11.
The current study was carried out to evaluate the pharmacological properties of cupincin- A novel cupin domain containing metalloprotease with limited proteolysis from rice bran on blood coagulation and hydrolysis of human fibrinogen. Cupincin preferentially hydrolyzed the Aα chain of fibrinogen and then the Bβ-chain, but not the γ-chain. Cupincin reduced the re-calcification time of citrated human plasma dose dependently. Analysis of citrated whole blood in the presence of cupincin by rotem showed a decrease in coagulation time and clot formation time. Sonoclot analysis indicated that cupincin cleaved fibrinogen of whole citrated blood. SDS-PAGE and sonoclot analysis (LI-30) indicated that cupincin lacked plasmin-like activity. Global hemostasis tests like rotem and sonoclot analysis determined cupincin as a procoagulant enzyme. Cupincin did not show any effect on prothrombin time and activated partial thromboplastin time tests suggesting its action on the common pathway of coagulation. The involvement of proteases from rice ( L.) in haemostasis has never been exploited before. This study could provide the basis for the development of new procoagulant agents from a nontoxic source like rice.
本研究旨在评估cupincin的药理学特性——一种来自米糠的含金属蛋白酶的新型cupin结构域，具有有限的蛋白水解作用，对血液凝固和人纤维蛋白原水解的影响。Cupincin优先水解纤维蛋白原的Aα链，然后是Bβ链，但不水解γ链。Cupincin剂量依赖性地缩短了枸橼酸化人血浆的再钙化时间。通过旋转血栓弹力图仪（rotem）分析在cupincin存在下的枸橼酸化全血，发现凝血时间和凝块形成时间缩短。声凝分析表明cupincin可裂解枸橼酸化全血中的纤维蛋白原。SDS-PAGE和声凝分析（LI-30）表明cupincin缺乏纤溶酶样活性。像旋转血栓弹力图仪（rotem）和声凝分析这样的整体止血测试确定cupincin是一种促凝血酶。Cupincin对凝血酶原时间和活化部分凝血活酶时间测试没有任何影响，表明其作用于凝血的共同途径。此前从未探索过水稻（L.）中的蛋白酶在止血方面的作用。本研究可为从水稻这种无毒来源开发新型促凝血剂提供依据。
