作者:Hye-Seon CHOI、You-Seon SA
DOI:10.1271/bbb.65.781
日期:2001.1
A fibrinolytic protease was purified from a Chinese herb (Spirodela polyrhiza). The protease has a molecular mass of 145 kDa and 70 kDa in gel filtration and SDS-polyacrlamide gel electrophoresis (PAGE), respectively, implying it is a dimer. Its optimum pH was 4.5-5.0 The enzyme was stable below 42°C and after lyophilization. The enzyme activity was inhibited significantly by leupeptin and aprotinin. The protease hydrolyzed not only fibrin but also fibrinogen, cleaving Aα and Bβ without affecting the γ chain of fibrinogen. It preferentially cleaved the peptide bond of Arg or Lys of synthetic substates (P1 position). The enzyme had an anticoagulating activity measured with activated partial thromboplastin time (APTT), thrombin time (TT), and prothrombin time (PT) tests. It delayed APTT, TT, and PT two times at the concentration of 36, 39, and 128 nM, respectively and this was drastically reduced after heat treatment.
从一种中草药(刺五加)中纯化出了一种纤维蛋白溶解蛋白酶。在凝胶过滤和 SDS 聚丙烯酰胺凝胶电泳(PAGE)中,该蛋白酶的分子质量分别为 145 kDa 和 70 kDa,这意味着它是一种二聚体。酶的最适 pH 值为 4.5-5.0,在 42°C 以下和冻干后稳定。利血平和阿普罗宁对酶的活性有明显的抑制作用。该蛋白酶不仅能水解纤维蛋白,还能水解纤维蛋白原,裂解 Aα 和 Bβ,而不影响纤维蛋白原的γ 链。它优先裂解合成亚基(P1 位)中 Arg 或 Lys 的肽键。通过活化部分凝血活酶时间(APTT)、凝血酶时间(TT)和凝血酶原时间(PT)测试,该酶具有抗凝活性。在浓度分别为 36、39 和 128 nM 时,它能将 APTT、TT 和 PT 的时间延迟两倍,而在加热处理后,这种延缓作用会急剧下降。