Sant'Ana Carolina D, Bernardes Carolina P, Izidoro Luiz Fernando M, Mazzi Maurício V, Soares Sandro G, Fuly André L, Zingali Russolina B, Magro Angelo J, Braz Antonio S K, Fontes Marcos R M, Stábeli Rodrigo G, Sampaio Suely V, Soares Andreimar M
Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto da Universidade de São Paulo, FCFRP-USP, Ribeirão Preto, SP, Brazil.
Biochimie. 2008 Mar;90(3):500-7. doi: 10.1016/j.biochi.2007.10.005. Epub 2007 Oct 18.
A thrombin-like enzyme, named BjussuSP-I, isolated from Bothrops jararacussu snake venom, is an acidic single-chain glycoprotein with M(r)=61,000, pI approximately 3.8 and 6% sugar. BjussuSP-I shows high proteolytic activity upon synthetic substrates, such as S-2238 and S-2288. It also shows procoagulant and kallikrein-like activity, but is unable to act on platelets and plasmin. These activities are inhibited by specific inhibitors of this class of enzymes. The complete cDNA sequence of BjussuSP-I with 696bp encodes open reading frames of 232 amino acid residues, which conserve the common domains of thrombin-like serine proteases. BjussuSP-I shows a high structural homology with other thrombin-like enzymes from snake venoms where common amino acid residues are identified as those corresponding to the catalytic site and subsites S1, S2 and S3 already reported. In this study, we also demonstrated the importance of N-linked glycans to improve thrombin-like activity of BjussuSP-I toxin.
一种从巴西矛头蝮蛇毒中分离出的类凝血酶，名为BjussuSP-I，是一种酸性单链糖蛋白，相对分子质量为61,000，等电点约为3.8，含糖量为6%。BjussuSP-I对合成底物（如S-2238和S-2288）具有较高的蛋白水解活性。它还表现出促凝血和类激肽释放酶活性，但不能作用于血小板和纤溶酶。这些活性受到这类酶的特异性抑制剂的抑制。BjussuSP-I的完整cDNA序列为696bp，编码232个氨基酸残基的开放阅读框，其保留了类凝血酶丝氨酸蛋白酶的常见结构域。BjussuSP-I与其他蛇毒类凝血酶具有高度的结构同源性，其中常见的氨基酸残基被鉴定为与已报道的催化位点以及S1、S2和S3亚位点相对应的残基。在本研究中，我们还证明了N-连接聚糖对提高BjussuSP-I毒素类凝血酶活性的重要性。
