Orientation of peptides in aqueous monolayer films. Infrared reflection-absorption spectroscopy studies of a synthetic amphipathic beta-sheet.
Orientation of peptides in aqueous monolayer films. Infrared reflection-absorption spectroscopy studies of a synthetic amphipathic beta-sheet.
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水性单层膜中肽的取向。
DOI：
10.1021/la0304316
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Mendelsohn,Richard
中科院分区：
文献类型：
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作者：
Xu,Zhi;Brauner,JosephW;Flach,CarolR;Mendelsohn,Richard
红外反射-吸收光谱（IRRAS）强度的酰胺I振动被用来开发一种定量的方法来确定欧拉角，描述蛋白质β-折叠在水单层膜的取向。合成的两亲性肽Val-Glu-Val-Orn-Val-Glu-Val-Orn-Val-Glu-Val-Orn-Val-OH用作测试情况。酰胺I频率的模式表明，分子在空气/水界面处被组织为反平行的β-折叠。用于模拟酰胺I强度的模型揭示β-折叠具有平行于压缩方向的轻微优先排列;即，观察到偏离单轴对称。此外，该片材被发现平放在水性表面上，（据推测）极性侧链与水性亚相相互作用。的理论方法的局限性和优点进行了讨论。
Infrared reflection−absorption spectroscopy (IRRAS) intensities of the Amide I vibration are used to develop a quantitative approach for determining the Euler angles that describe the orientation of protein β-sheets in aqueous monolayer films. A synthetic amphipathic peptide, Val-Glu-Val-Orn-Val-Glu-Val-Orn-Val-Glu-Val-Orn-Val-OH is used as a test case. The pattern of Amide I frequencies suggests that the molecule is organized as an antiparallel β-sheet at the air/water interface. The model used to simulate the Amide I intensities reveals that the β-sheet has a slight preferential alignment parallel to the direction of compression; i.e., deviation from uniaxial symmetry is observed. In addition, the sheet is found to lie flat on the aqueous surface, with (presumably) the polar side chains interacting with the aqueous subphase. Limitations and advantages of the theoretical approach are discussed.