The role of esterification on detection of protonated and deprotonated peptide ions in matrix assisted laser desorption/ionization (MALDI) mass spectrometry (MS)
The role of esterification on detection of protonated and deprotonated peptide ions in matrix assisted laser desorption/ionization (MALDI) mass spectrometry (MS)
复制标题
DOI：
10.1016/j.jasms.2005.03.019
复制
发表时间：
2005-08-01
影响因子：
3.2
通讯作者：
Brancia, FL
中科院分区：
文献类型：
--
作者：
Lecchi, P;Olson, M;Brancia, FL
酯化是用来研究如何引入的肽结构内的脂肪链影响的MALDI响应的离子分析在两个极性制度。在含有等摩尔量的肽与其相应的烷基酯的二元混合物中，羧基的衍生化具有增加修饰的质子化肽离子的MALDI检测的趋势。当使用较长的醇时，这种对离子产率的积极影响更加明显。在负模式下，情况是相反的，酯化对相应的去质子化物质的离子产率产生有害影响。从这里报告的数据，我们假设，修改的酸性特征的肽防止阴离子物质的形成下MALDI分析。此外，抑制阴离子的形成途径改变了可以进行质子化的分子的总数。这导致质子化酯的离子产率增加。
Esterification was used to investigate how introduction of aliphatic chains within the peptide structure affects the MALDI response of ions analyzed in both polarity regimes. In binary mixtures containing equimolar amounts of a peptide with its correspondent alkyl ester, derivatization of the carboxylic groups has the tendency to increase MALDI detection of the modified protonated peptide ions. This positive effect on ion yield is more pronounced when longer alcohols are employed. In negative mode, the situation is antithetic and esterification produces a deleterious effect on the ion yield of the corresponding deprotonated species. From the data reported here we postulate that modifications of the acidic character of peptides prevent formation of anionic species under MALDI analysis. Furthermore, suppression of the formation pathway for anions alters the overall number of molecules which can undergo protonation. This results in an increased ion yield for the protonated esters.