Neutron crystallographic evidence of lipase-colipase complex activation by a micelle
Neutron crystallographic evidence of lipase-colipase complex activation by a micelle
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DOI：
10.1093/emboj/16.18.5531
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发表时间：
1997-09-15
期刊：
影响因子：
11.4
通讯作者：
FontecillaCamps, JC
中科院分区：
文献类型：
--
作者：
Hermoso, J;Pignol, D;FontecillaCamps, JC
脂肪酶界面活化的概念源于发现大多数脂肪酶的催化活性取决于其底物的聚集状态。据认为，激活涉及通过构象变化需要存在的水包油液滴的酶的活性位点的掩蔽和结构化，在这里，我们提出了使用D2 O/H2O对比度变化低分辨率衍射方法确定的激活的脂肪酶-辅脂酶-胶束复合物的中子结构，在三元复合物中，盘状胶束与辅脂酶的凹面和脂肪酶的C-末端结构域的远端广泛地相互作用。由于胶束和底物的结合位点涉及不同区域的蛋白质复合物，我们得出结论，脂肪酶的激活不是界面，但发生在水相，并介导的辅脂酶和胶束。
The concept of lipase interfacial activation stems from the finding that the catalytic activity of most lipases depends on the aggregation state of their substrates. It is thought that activation involves the unmasking and structuring of the enzyme's active site through conformational changes requiring the presence of oil-in-water droplets, Here, we present the neutron structure of the activated lipase-colipase-micelle complex as determined using the D2O/H2O contrast variation low resolution diffraction method, In the ternary complex, the disk-shaped micelle interacts extensively with the concave face of colipase and the distal tip of the C-terminal domain of lipase. Since the micelle-and substrate-binding sites concern different regions of the protein complex, we conclude that lipase activation is not interfacial but occurs in the aqueous phase and is mediated by colipase and a micelle.