SOLVENT-INDUCED CONFORMATIONAL-CHANGES OF POLYPEPTIDES PROBED BY ELECTROSPRAY-IONIZATION MASS-SPECTROMETRY
SOLVENT-INDUCED CONFORMATIONAL-CHANGES OF POLYPEPTIDES PROBED BY ELECTROSPRAY-IONIZATION MASS-SPECTROMETRY
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DOI：
10.1002/rcm.1290050303
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发表时间：
1991-03-01
影响因子：
2
通讯作者：
SMITH, RD
中科院分区：
文献类型：
--
作者：
LOO, JA;LOO, RRO;SMITH, RD
电喷雾电离 (ESI) 质谱用于监测由于蛋白质溶液环境中 pH 值或有机溶剂组成的改变而引起的多肽的高级结构变化。在含有少量 (< 20%) 有机溶剂的溶液中，泛素（相对分子质量 8565）的 ESI 质谱中观察到双峰电荷态分布。高 m/z（低电荷态）峰的分布代表了蛋白质的天然球状状态；较高电荷态分布是更扩展构象的特征。需要添加超过 40% v/v 的甲醇变性剂才能完全消除低电荷态分布。需要较少量的乙腈、丙酮或异丙醇（约 20%）来使 Unibquitin 蛋白变性。还说明了在 ESI 质谱中显示构象效应的其他蛋白质。虽然ESI光谱与溶液相结构有关，但不同构象的多电荷分子离子的ESI串联质谱被建议作为气相蛋白质三维结构的探针。
Electrospray-ionization (ESI) mass spectrometry is used to monitor higher order structural changes of polypeptides induced by alteration of the pH or organic solvent composition in the protein solution environment. A bimodal charge-state distribution is observed in the ESI mass spectrum of ubiquitin (relative molecular mass 8565) in solutions containing small amounts (< 20%) of organic solvents. The distribution of peaks at high m/z (low-charge state) is found to represent the protein in its native, globular state; the higher-charge-state distribution is characteristic for a more extended conformation. Addition of methanol denaturant in excess of 40% v/v is needed to eliminate the low-charge-state distribution completely. Lesser amounts of acetonitrile, acetone, or isopropanol (approximately 20%) are required to denature the unibquitin protein. Other proteins showing conformational effects in their ESI mass spectra are also illustrated. While the ESI spectra are related to solution phase structure, ESI-tandem mass spectrometry of multiply charged molecular ions of different conformation is suggested as a probe of gas-phase protein three-dimensional structure.