Low-frequency modes of peptides and globular proteins in solution observed by ultrafast OHD-RIKES Spectroscopy
Low-frequency modes of peptides and globular proteins in solution observed by ultrafast OHD-RIKES Spectroscopy
复制标题
DOI：
10.1016/s0006-3495(03)74618-9
复制
发表时间：
2003-09-01
影响因子：
3.4
通讯作者：
Wynne, K
中科院分区：
文献类型：
--
作者：
Giraud, G;Karolin, J;Wynne, K
用超快光学外差探测拉曼诱导克尔效应光谱（OHD-RIKES）研究了溶液中多肽和蛋白质的低频（1-200 cm（-1））振动光谱。获得了二-L-丙氨酸（ALA（2））和α-螺旋肽聚-L-丙氨酸（PLA）在二氯乙酸溶液中的光谱。与二-L-丙氨酸光谱相比，聚-L-丙氨酸光谱显示出额外的振幅，这可以通过前者的二级结构来解释。研究了球形蛋白质溶菌酶、α-乳白蛋白、胃蛋白酶和β-乳球蛋白在水溶液中的低频光谱，以确定二级或三级结构对低频光谱的可能影响。用三个非扩散布朗振子分析了球状蛋白质的光谱。最低频率的振子对应于在非弹性中子散射（INS）中观察到的所谓玻色子峰。剩下的两个振子在非弹性中子散射中没有观察到，因此不涉及氢原子的显著运动，并且可能与离域骨架扭转有关。
The low-frequency (1-200 cm(-1)) vibrational spectra of peptides and proteins in solution have been investigated with ultrafast optical heterodyne-detected Raman-induced Kerr-effect spectroscopy (OHD-RIKES). Spectra have been obtained for di-L-alanine (ALA(2)) and the alpha-helical peptide poly-L-alanine (PLA) in dichloroacetic acid solution. The poly-L-alanine spectrum shows extra amplitude compared to the di-L-alanine spectrum, which can be explained by the secondary structure of the former. The globular proteins lysozyme, alpha-lactalbumin, pepsin, and beta-lactoglobulin in aqueous solution have been studied to determine the possible influence of secondary or tertiary structure on the low-frequency spectra. The spectra of the globular proteins have been analyzed in terms of three nondiffusive Brownian oscillators. The lowest frequency oscillator corresponds to the so-called Boson peak observed in inelastic neutron scattering ( INS). The remaining two oscillators are not observed in inelastic neutron scattering, do therefore not involve significant motion of hydrogen atoms, and may be associated with delocalized backbone torsions.