Conformational study of sequential Lys and Leu based polymers and oligomers using vibrational and electronic CD spectra.
Conformational study of sequential Lys and Leu based polymers and oligomers using vibrational and electronic CD spectra.
复制标题
使用振动和电子 CD 光谱对基于赖氨酸和亮氨酸的连续聚合物和低聚物进行构象研究。
DOI：
10.1002/bip.360340815
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发表时间：
1994
期刊：
影响因子：
2.9
通讯作者：
Brack,A
中科院分区：
文献类型：
--
作者：
Baumruk,V;Huo,D;Dukor,RK;Keiderling,TA;Lelievre,D;Brack,A
研究了一些连续的基于Lys和Leu的寡肽和多肽的振动CD（VCD）和电子CD（ECD）光谱作为添加盐的函数和（对于ECD）作为水溶液中浓度的函数。对于这些样品，VCD光谱只能在相对高的浓度下测量，在该浓度下，可以观察到KL基物质的众所周知的盐诱导转变为β折叠形式，但对于LKKL基样品，只有终态α螺旋构象是明显的。ECD浓度依赖性表明，在不添加盐或添加盐的高浓度下，基于LKKL的低聚物和聚合物产生α-螺旋光谱。这些数据提供了在异常简单的肽系统中聚集诱导二级结构形成的证据。类似地，基于KL的低聚物和聚合物在高浓度或高盐下产生β折叠状光谱。这些系统进一步提供了在“正常”水性条件下的模型系统，其产生与多肽的主要二级结构类型相关的VCD带形状。它们与在均聚多肽和蛋白质上获得的光谱基本一致，证实了VCD技术相对独立于侧链和溶剂效应。John Wiley & Sons，Inc.
Vibrational CD (VCD) and electronic CD (ECD) spectra of some sequential Lys and Leu based oligo‐ and polypeptides were studied as a function of added salt and (for ECD) as a function of concentration in aqueous solution. For these samples, the VCD spectra can only be measured at relatively high concentrations under which the well‐known salt‐induced transition to a β‐sheet form can be observed for the KL based species, but only the end‐state α‐helical conformation is obvious for the LKKL based samples. ECD concentration dependence demonstrates that, at high concentration with no added or with added salt, LKKL based oligomers and polymers give α‐helical spectra. These data provide evidence of aggregation induced secondary structure formation in an exceptionally simple peptide system. Similarly, the KL based oligomers and polymers give β‐sheet like spectra at high concentration or at high salt. These systems further provide model systems under “normal” aqueous conditions that yield VCD band shapes that correlate to the major secondary structural types of polypeptides. They are in substantial agreement with those spectra obtained on homopolypeptides and on proteins, confirming the relative independence of the VCD technique from side‐chain and solvent effects. © 1994 John Wiley & Sons, Inc.