Intra-residue interactions in proteins: interplay between serine or cysteine side chains and backbone conformations, revealed by laser spectroscopy of isolated model peptides
Intra-residue interactions in proteins: interplay between serine or cysteine side chains and backbone conformations, revealed by laser spectroscopy of isolated model peptides
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DOI：
10.1039/c4cp04449e
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发表时间：
2015-01-01
影响因子：
3.3
通讯作者：
Mons, Michel
中科院分区：
文献类型：
--
作者：
Alauddin, Mohammad;Biswal, Himansu S.;Mons, Michel
残基内相互作用通过影响骨架的局部折叠在蛋白质中发挥重要作用。利用气相实验提供分离肽链固有氢键模式的相关信息，用激光光谱学方法研究了丝氨酸和半胱氨酸残基之间的相互作用，即丝氨酸/半胱氨酸残基中的OH/SH中心点OC(I)C6和NH(I)中心点O/S C5相互作用。这些局部侧链-主链相互作用的强度，从主链明确构象的红外光谱特征中得到了优雅的记录，表明两种类型的残基键之间存在着微妙的竞争：C6H键是与Ser的主要相互作用，而Cys则由C5相互作用占据主导地位。在与Ser和Cys的气相实验中观察到的有限的构象数量(同时观察到延伸和折叠的形式)也表明这些残基内的相互作用对几种主链折叠模式之间的竞争具有显著的调节作用。
Intra-residue interactions play an important role in proteins by influencing local folding of the backbone. Taking advantage of the capability of gas phase experiments to provide relevant information on the intrinsic H-bonding pattern of isolated peptide chains, the intra-residue interactions of serine and cysteine residues, i.e., OH/SH center dot center dot center dot OC(i) C6 and NH(i)center dot center dot center dot O/S C5 interactions in Ser/Cys residues, are probed by laser spectroscopy of isolated peptides. The strength of these local side chain-main chain interactions, elegantly documented from their IR spectral features for well-defined conformations of the main chain, demonstrates that a subtle competition exists between the two types of intra-residue bond: the C6 H-bond is the major interaction with Ser, in contrast to Cys where C5 interaction takes over. The restricted number of conformers observed in the gas phase experiment with Ser compared to Cys (where both extended and folded forms are observed) also suggests a significant mediation role of these intra-residue interactions on the competition between the several main chain folding patterns.