克隆、表达、纯化和表征鲁兹锥体的triosephosphate异构酶。
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Ostoa-Saloma P, Garza-Ramos G,拉米雷斯J,贝克尔,Berzunza M,兰达,Gomez-Puyou, Tuena de Gomez-Puyou M, Perez-Montfort R
克隆、表达、纯化和表征鲁兹锥体的triosephosphate异构酶。
3月15日。1997欧元;244 (3):700 - 5。
- PubMed ID
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9108237 (在PubMed]
- 文摘
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triosephosphate异构酶的基因编码鲁兹锥体是克隆和测序。在t . cruzi,只有一个triosephosphate异构酶的基因。72%和68%的酶有身份triosephosphate异构酶从锥虫属brucei和利什曼虫墨西哥,分别。的活性位点残基是守恒:32残留符合接口的二聚的triosephosphate异构酶从t . brucei 29 t . cruzi酶是守恒的。这种酶在大肠杆菌表达和纯化同质性。在变性电泳分析技术和数据过滤技术表明,从t . cruzi triosephosphate异构酶为。它的一些结构和动力学特性测定和比较的纯化酶从t . brucei和l .墨西哥。它的圆二色性光谱几乎相同的triosephosphate从t . brucei异构酶。其动力学特性和pH值最适条件类似t brucei l .墨西哥,尽管后者表现出更高的Vmax甘油醛3 -磷酸为底物。三种酶的巯基试剂的敏感性methylmethane thiosulfonate (MeSO2-SMe)决定; the sensitivity of the T. cruzi enzyme was about 40 times and 200 times higher than that of the enzymes from T. brucei and L. mexicana, respectively. Triosephosphate isomerase from T. cruzi and L. mexicana have the three cysteine residues that exist in the T. brucei enzyme (positions 14, 39, 126, using the numbering of the T. brucei enzyme); however, they also have an additional residue (position 117). These data suggest that regardless of the high identity of the three trypanosomatid enzymes, there are structural differences in the disposition of their cysteine residues that account for their different sensitivity to the sulfhydryl reagent. The disposition of the cysteine in triosephosphate isomerase from T. cruzi appears to make it unique for inhibition by modification of its cysteine.