MULTIPLY CHARGED NEGATIVE-IONS BY ELECTROSPRAY IONIZATION OF POLYPEPTIDES AND PROTEINS
MULTIPLY CHARGED NEGATIVE-IONS BY ELECTROSPRAY IONIZATION OF POLYPEPTIDES AND PROTEINS
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DOI：
10.1021/ac00025a015
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发表时间：
1992-01-01
影响因子：
7.4
通讯作者：
SMITH, RD
中科院分区：
文献类型：
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作者：
LOO, JA;LOO, RRO;SMITH, RD
通过电喷雾电离-质谱法（ESI-MS）分析从pH约11的水溶液产生的多重去质子化的多肽和蛋白质分子（M-nH）n-。氢氧化铵水溶液的分析物被证明是优选的氢氧化钠溶液的负离子ESI由于生产的multiplesodiated蛋白质物种从后者的系统。已检测到M（r）为66000且具有多达57个负电荷的蛋白质。多电荷负离子可以从高酸性蛋白胃蛋白酶（M（r）约34600）的ESI产生，因为其相对大量的酸性残基，42。相比之下，胃蛋白酶（4）的碱性氨基酸残基数量较少，不允许形成对于有限m/z范围的质谱仪的正离子检测必不可少的高度质子化物质。同样，负离子ESI-MS也可用于大寡糖分析。多电荷多肽阴离子的初步串联质谱实验证明了负离子ESI-MS用于结构解析的实用性和潜力。
Multiply deprotonated polypeptide and protein molecules, (M - nH)n-, produced from pH approximately 11 aqueous solutions, are analyzed by electrospray ionization-mass spectrometry (ESI-MS). Aqueous ammonium hydroxide solutions of the analyte are shown to be preferable to sodium hydroxide solutions for negative-ion ESI due to the production of multiply sodiated protein species from the latter system. Proteins with M(r) to 66000 and having up to 57 negative charges have been detected. Multiply charged negative ions can be produced from ESI of the highly acidic protein pepsin (M(r) approximately 34600) because of its relatively large number of acidic residues, 42. In contrast, the small number of basic amino acid residues for pepsin (4) does not allow formation of highly protonated species essential for positive-ion detection, for mass spectrometers of limited m/z range. Similarly, negative-ion ESI-MS is extended to large oligosaccharide analysis. Preliminary tandem mass spectrometry experiments of multiply charged polypeptide anions demonstrate the utility and potential of negative-ion ESI-MS for structural elucidation.