假单胞菌脂肪酶的开放构型。
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朗施拉格JD,李Y, Cygler M, D, b . T,赫克特HJ,施密德R,才D, Rydel TJ,奥利弗JD,斯特里克兰LC, Dunaway厘米,拉尔森某人,天J,麦克弗森
假单胞菌脂肪酶的开放构型。
结构。1997年2月15日,5 (2):187 - 202。
- PubMed ID
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9032074 (在PubMed]
- 文摘
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背景:。脂酶结果的界面激活主要从酶的构象变化,暴露的活性部位,并提供一个疏水表面与脂质衬底的交互。比较使用的结晶条件和各种脂酶的结构观察表明,酶的构象条件取决于解决方案。假单胞菌不过脂肪酶(PCL)结晶在开放的条件下,酶的活性构象。其三维结构决定在三个独立的实验室,并与之前报道相比封闭构象密切相关的脂酶从假单胞菌glumae (PGL)和色素细菌viscosum (CVL)。这些结构提供新的见解这商业上重要的脂酶家族的功能。结果:。PCL的三个独立结构重叠mainchain构象只有微小的差异。正如所料,观察到的构象揭示了一个催化部位暴露在溶剂。叠加的PCL PGL和CVL结构表明重排从封闭到开放构型涉及三个循环。 The largest movement involves a 40 residue stretch, within which a helical segment moves to afford access to the catalytic site. A hydrophobic cleft that is presumed to be the lipid binding site is formed around the active site. CONCLUSIONS: . The interfacial activation of Pseudomonas lipases involves conformational rearrangements of surface loops and appears to conform to models of activation deduced from the structures of fungal and mammalian lipases. Factors controlling the conformational rearrangement are not understood, but a comparison of crystallization conditions and observed conformation suggests that the conformation of the protein is determined by the solution conditions, perhaps by the dielectric constant.