Molecular interaction of imino sugars with human α-galactosidase: Insight into the mechanism of complex formation and pharmacological chaperone action in Fabry disease
Molecular interaction of imino sugars with human α-galactosidase: Insight into the mechanism of complex formation and pharmacological chaperone action in Fabry disease
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DOI：
10.1016/j.ymgme.2008.12.017
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发表时间：
2009-04-01
影响因子：
3.8
通讯作者：
Sakuraba, Hitoshi
中科院分区：
文献类型：
--
作者：
Sugawara, Kanako;Tajima, Youichi;Sakuraba, Hitoshi
酶增强疗法（EET）是一种治疗法布里病的新方法。人们认为亚氨基糖在细胞中作为野生型和突变型α -半乳糖苷酶（GLAs）的药理学伴侣，但亚氨基糖和酶之间分子相互作用的机制尚未明确。我们检测了各种亚氨基糖，发现半乳糖抑制素亚硫酸酯（GBS）在体外抑制GLA，并增加培养法布里成纤维细胞的酶活性，如1-脱氧半乳糖吉里霉素（DGJ）。然后，我们利用等温滴定量热法和表面等离子体共振生物传感器分析了亚氨基糖与重组人GLA的分子相互作用，并首先确定了亚氨基糖与GLA复合物形成的热力学和结合动力学参数。结果表明，DGJ与酶的结合比GBS更强，DGJ与酶蛋白的结合是由焓驱动的。对于GBS，反应主要是焓驱动的。但有一种可能性是，熵驱动因素参与了这种结合。二氧化硅的结构分析表明，这两种化学物质都适合于活性位点口袋，并与构成活性位点口袋的残基（包括催化残基）发生氢键。GBS侧链面向活性位点袋的入口，因此可以与构成活性位点袋壁的残基接触。热力学、动力学和结构方面的研究将为改善法布里病的EET治疗提供大量信息。(C) 2009爱思唯尔公司版权所有。
Enzyme enhancement therapy (EET) for Fabry disease involving imino sugars has been developed and attracted interest. It is thought that imino sugars act as pharmacological chaperones for wild-type and mutant alpha-galactosidases (GLAs) in cells, but the mechanisms underlying the molecular interactions between the imino sugars and the enzyme have not been clarified yet. We examined various kinds of imino sugars and found that galactostatin bisulfite (GBS) inhibited GLA in vitro and increased the enzyme activity in cultured Fabry fibroblasts as in the case of 1-deoxygalactonojirimycin (DGJ). Then, we analyzed the molecular interactions between the imino sugars and recombinant human GLA by means of isothermal titration calorimetry and surface plasmon resonance biosensor assays, and first determined the thermodynamic and binding-kinetics parameters of imino sugar and GLA complex formation. The results revealed that DGJ bound to the enzyme more strongly than GBS, the binding of DGJ to the enzyme protein being enthalpy-driven. In the case of GBS, the reaction was mainly enthalpy-driven. but there was a possibility that entropy-driven factors were involved in the binding. Structural analysis in silica revealed that both the chemicals fit into the active-site pocket and undergo hydrogen bonding with residues comprising the active-site pocket including the catalytic ones. The side chain of GBS was oriented towards the entrance of the active-site pocket, and thus it could be in contact with residues comprising the wall of the active-site pocket. Thermodynamic, kinetic and structural studies should provide us with a lot of information for improving EET for Fabry disease. (C) 2009 Elsevier Inc. All rights reserved.