Effects of acidic peptide size and sequence on trivalent praseodymium adduction and electron transfer dissociation mass spectrometry.
Effects of acidic peptide size and sequence on trivalent praseodymium adduction and electron transfer dissociation mass spectrometry.
复制标题
酸性肽大小和序列对三价镨加合和电子转移解离质谱的影响。
DOI：
10.1002/jms.3919
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Cassady,CarolynJ
中科院分区：
文献类型：
--
作者：
Commodore,JulietteJ;Cassady,CarolynJ
用稀土离子镨、镨（Ⅲ）、金属离子形成和电子转移解离（ETD）对25种生物和模型酸性肽进行了研究。对于七个或更多残基的链长度，即使是难以通过电喷雾电离质子化的高酸性肽也会金属化并经历丰富的ETD片段化。主要由酸性残基组成的肽仅形成去质子化离子[M + Pr-H]2+;该离子产生较大肽的几乎完整的ETD序列覆盖。具有酸性和中性残基的混合物的肽产生[M + Pr]3+，其在许多肽的每个残基之间裂解。含有至少一个具有碱性侧链的残基的酸性肽也产生质子化离子[M + Pr + H]4+;该离子通过ETD经历最广泛的序列覆盖。对于所有研究的肽，主要是金属化和非金属化的c和z离子形式。只有当至少一半的肽序列可以掺入离子中时，才存在金属加合物产物离子;这表明金属离子同时附着在一个以上的酸性位点上。唯一始终缺乏解离的位点是在脯氨酸残基的N末端侧。对于具有相同电荷状态的金属-肽复合物，增加肽链长度产生更多的骨架裂解。对于具有相同长度的酸性肽，将前体离子电荷状态从2+增加到3+也导致更多的切割。这项研究的结果表明，高酸性肽可以通过与Pr（III）形成的复合物的ETD进行测序。版权所有© 2017约翰威利父子有限公司
Using the lanthanide ion praseodymium, Pr(III), metallated ion formation and electron transfer dissociation (ETD) were studied for 25 biological and model acidic peptides. For chain lengths of seven or more residues, even highly acidic peptides that can be difficult to protonate by electrospray ionization will metallate and undergo abundant ETD fragmentation. Peptides composed of predominantly acidic residues form only the deprotonated ion, [M + Pr ‐ H]2+; this ion yields near complete ETD sequence coverage for larger peptides. Peptides with a mixture of acidic and neutral residues generate [M + Pr]3+, which cleaves between every residue for many peptides. Acidic peptides that contain at least one residue with a basic side chain also produce the protonated ion, [M + Pr + H]4+; this ion undergoes the most extensive sequence coverage by ETD. Primarily metallated and non‐metallated c‐ and z‐ions form for all peptides investigated. Metal adducted product ions are only present when at least half of the peptide sequence can be incorporated into the ion; this suggests that the metal ion simultaneously attaches to more than one acidic site. The only site consistently lacking dissociation is at the N‐terminal side of a proline residue. Increasing peptide chain length generates more backbone cleavage for metal‐peptide complexes with the same charge state. For acidic peptides with the same length, increasing the precursor ion charge state from 2+ to 3+ also leads to more cleavage. The results of this study indicate that highly acidic peptides can be sequenced by ETD of complexes formed with Pr(III). Copyright © 2017 John Wiley & Sons, Ltd.