Two-Dimensional/Attenuated Total Reflection Infrared Correlation Spectroscopy Studies on Secondary Structural Changes in Human Serum Albumin in Aqueous Solutions: pH-Dependent Structural Changes in the Secondary Structures and in the Hydrogen Bondings of Side Chains
Two-Dimensional/Attenuated Total Reflection Infrared Correlation Spectroscopy Studies on Secondary Structural Changes in Human Serum Albumin in Aqueous Solutions: pH-Dependent Structural Changes in the Secondary Structures and in the Hydrogen Bondings of Side Chains
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DOI：
10.1021/jp004537a
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发表时间：
2001-04
影响因子：
3.3
通讯作者：
K. Murayama;Yuqing Wu;†‖ and Bogusława Czarnik-Matusewicz;Y. Ozaki
中科院分区：
文献类型：
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作者：
K. Murayama;Yuqing Wu;†‖ and Bogusława Czarnik-Matusewicz;Y. Ozaki
在pH值为5.0−3.2的水溶液中测量了人血清白蛋白的衰减全反射/红外光谱。用广义二维(2D)相关分析研究了HSA二级结构和侧链氢键随pH的变化。从人血清白蛋白的N异构体(pH 5.0−4.4)、N−F跃迁(pH 4.6−3.8)和F异构体(pH 3.8−3.0)三种状态的光谱变化中获得了同步和非同步的2D光谱。2D谱中最有趣的发现是在1740、1715、1705和1696 cm-1处发现了四个带，这是由于HSA的自由和氢键(弱、中、强)COOH基团的CO伸缩模式。二维相关分析为至少存在四个CO谱带提供了明确的证据，显示了其强大的反褶积能力。N型的异步谱具有一定的特征。
Attenuated total reflection (ATR)/infrared (IR) spectra were measured for human serum albumin (HSA) in aqueous solutions over a pH range of 5.0−3.2. Generalized two-dimensional (2D) correlation analysis was applied to the amide I region of the spectra to investigate pH-dependent changes in secondary structures and in hydrogen bondings of side chains of HSA. The synchronous and asynchronous 2D spectra were generated from the pH-dependent spectral variations for the three states of HSA, the N isomeric form (pH 5.0−4.4), the N−F transition (pH 4.6−3.8), and the F isomeric form (pH 3.8−3.0). The most interesting finding in the 2D spectra is identification of four bands at 1740, 1715, 1705, and 1696 cm-1 due to a CO stretching mode of free and hydrogen bonded (weak, medium, and strong) COOH groups of HSA. The 2D correlation analysis provides unambiguous evidence for the existence at least the four CO bands, demonstrating its powerful deconvolution ability. The asynchronous spectrum of the N form is characteriz...