Circular dichroism and Fourier transform infrared spectroscopic studies on self-assembly of tetrapeptide derivative in solution and solvated film
Circular dichroism and Fourier transform infrared spectroscopic studies on self-assembly of tetrapeptide derivative in solution and solvated film
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DOI：
10.1034/j.1399-3011.2003.00039.x
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发表时间：
2003-03-01
期刊：
影响因子：
--
通讯作者：
Jayakumar, R
中科院分区：
文献类型：
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作者：
Ganesh, S;Jayakumar, R
研究了疏水肽衍生物Boc-Ala-Ile-Ile-Gly-OMe（1）在甲醇溶液和溶剂化膜状态下的聚集。使用荧光[8-苯胺基-萘磺酸（ANS）的镁盐作为外部探针]和圆二色性（CD）光谱技术证明通过自组装形成肽。在溶液中，肽1以约3 × 10（-4）M浓度形成稳定的聚集体。肽凝胶成薄膜，我们进行了CD和傅里叶变换红外（FTIR）测量。我们的光谱研究在不同的甲醇浓度的肽膜表明，在溶剂化的薄膜中，随着甲醇浓度的降低，肽的螺旋含量降低。然而，通过降低甲醇浓度，我们能够观察到通过无规卷曲构象从主要螺旋转向到β-折叠结构的构象转变。我们的研究集中在α-螺旋转角形成肽衍生物的聚集，其显示在膜形式中改变溶剂浓度的构象转变。
Aggregation of the hydrophobic peptide derivative Boc-Ala-Ile-Ile-Gly-OMe (1) was examined in methanol solution and in solvated film states. Formation of the peptide by self-assembly was evidenced using fluorescence [Mg salt of 8-anilino-naphthalenesulfonic acid (ANS) as an external probe] and circular dichroism (CD) spectroscopic techniques. in solution, peptide 1 formed as a stable aggregate at a concentration around 3 x 10(-4) M. The peptide gelled into a thin film for which we carried out CD and Fourier transform infrared (FTIR) measurements. Our spectroscopic study on peptide films at differing methanol concentrations indicates that the helical content of the peptide decreases with decreasing methanol concentration in solvated films. However, by reducing the methanol concentration we were able to observe a conformational transition from a predominantly helical turn to a beta-sheet structure via a random coil conformation. Our study focused on the aggregation of the alpha-helical turn-forming peptide derivative, which shows conformational transition on changing solvent concentration in the film form.