Colloidal Assembly of Proteins with Delaminated Lamellas of Layered Metal Hydroxide
Colloidal Assembly of Proteins with Delaminated Lamellas of Layered Metal Hydroxide
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具有层状金属氢氧化物分层薄片的蛋白质的胶体组装
DOI：
10.1021/la901205c
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发表时间：
2009-09-15
期刊：
影响因子：
3.9
通讯作者：
Wang, Yan
中科院分区：
文献类型：
--
作者：
An, Zhe;Lu, Shan;Wang, Yan
胶体LDH纳米片已组装在水介质中与三种蛋白质具有不同的结构和表面电荷分布。除了界面吸附的功能，二级和/或更高层次的结构的表面结合蛋白质的ATR-FTIR和荧光光谱技术进行了研究。猪胰脂肪酶（PPL）的结构和构象得到了很好的保留，其负电荷集中在活性中心的相对侧表面，但PPL分子在二维LDH纳米片上的取向可以是平放或直立，这取决于PPL/LDH的比例。与可溶性PPL相比，PPL的生物活性在水解和动力学拆分中均得到增强。在血红蛋白（Hb）的情况下，四聚体血红素蛋白具有相对均匀的表面负电荷分布，界面组装可能导致其三级或四级结构的解折叠，但其二级结构和氧化还原活性血红素基团不会变性。尽管牛血清白蛋白（BSA）的二级结构（其中负电荷沿着线性排列的结构域I和II的表面分布）是展开的，但由于二维LDH纳米片表面的曲率较小，有序结构的损失小于先前发现的。这是第一个报告有关的研究蛋白质的结构，构象和方向的生物杂化材料组成的LDH纳米片。
The colloidal LDH nanosheets have been assembled in aqueous medium with three proteins having different structures and surface charge distributions. In addition to the interfacial adsorption features, the secondary and/or higher level structures of surface-bound proteins are investigated by ATR-FTIR and fluorescence spectroscopic techniques. The structure and conformation of porcine pancreatic lipase (PPL), for which the negative charges are concentrated on the side surface opposite to active sites, are well retained, but the orientations of PPL molecules on two-dimensional LDH nanosheets could be lying flat or standing up depending on the PPL/LDH ratio. The bioactivity of PPL lying flat is enhanced in both the hydrolysis and kinetic resolution in comparison with its soluble Counterpart. In the case of hemoglobin (Hb), a tetrameric hemeprotein With relatively uniform distribution of surface negative charges, the interfacial assembly might result in the unfolding of its tertiary or quaternary structure, but its secondary structure and redox-active heme groups are not denatured. Although the secondary structure of bovine serum albumin (BSA), for which the negative charges are distributed along the surfaces of linearly arranged domains I and II, is unfolded, the loss of the ordered structure is less than previously found owing to the less curvature of the two-dimensional LDH nanosheet surface. This is the first report related to the investigations of protein structures, conformations, and orientations in the biohybrids consisting of LDH nanosheets.