Hydrogen bonding and equilibrium isotope enrichment in histidine-containing proteins
Hydrogen bonding and equilibrium isotope enrichment in histidine-containing proteins
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DOI：
10.1038/nsb0696-522
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发表时间：
1996-06-01
期刊：
影响因子：
--
通讯作者：
Klevit, RE
中科院分区：
文献类型：
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作者：
Bowers, PM;Klevit, RE
我们使用 NMR 和质谱法测量了三种含组氨酸的蛋白质（ecHPr、ecHPr 突变体 S31A 和 bsHPr）以及无规卷曲肽中的氘/氢分级。非结构化肽的酰胺质子表现出氘的平衡富集，与之前的研究一致。在两个 HPr 中均观察到氕和氘的富集，分馏因子范围为 0.63 至 1.41。在α-螺旋二级结构中观察到氕的富集。先前通过诱变和热力学测量鉴定出的“强”HBs 显着富集了氕。尽管 ecHPr 和 bsHPr 仅具有 30% 的序列同一性，但氕富集位点在跨物种系的结构背景中是保守的，这表明强 HBs 是保守的，并且可能在稳定折叠状态中发挥重要作用。
We have measured deuterium/hydrogen fractionation in three histidine-containing proteins, ecHPr, ecHPr mutant S31A, and bsHPr, and in random coil peptides using NMR and mass spectrometry. The amide protons of unstructured peptides exhibit equilibrium enrichment for deuterium, in agreement with previous studies. Enrichment for both protium and deuterium was observed in both HPrs, with fractionation factors ranging from 0.63 to 1.41. Enrichment for protium was seen in a-helical secondary structure. 'Strong' HBs previously identified by mutagenesis and thermodynamic measurements are significantly enriched for protium. Sites of protium enrichment are conserved in a structural context across species lines, though ecHPr and bsHPr share only 30% sequence identity, suggesting that strong HBs are conserved and may play an important role in stabilizing the folded state.