Broadband detection electrospray ionization fourier transform ion cyclotron resonance mass spectrometry to reveal enzymatically and chemically induced deamidation reactions within peptides
Broadband detection electrospray ionization fourier transform ion cyclotron resonance mass spectrometry to reveal enzymatically and chemically induced deamidation reactions within peptides
复制标题
DOI：
10.1021/ac0104274
复制
发表时间：
2001-12-15
影响因子：
7.4
通讯作者：
Jung, G
中科院分区：
文献类型：
--
作者：
Schmid, DG;von der Mülbe, F;Jung, G
在多肽或蛋白质的多种化学降解形式中，脱酰胺是最常观察到的一种变化。在这个不可逆反应中，谷氨酰胺或天冬酰胺侧链分别水解为谷氨酸或天冬氨酸（NH2转化为OH）。除了对生物技术和食品产品的变质有影响外，脱酰胺还代表了蛋白质组学中定义的翻译后修饰反应。在这里，质谱技术在确定翻译后修饰方面起着主导作用。然而，并不是所有的质谱仪都能分辨出0.0193 Da (（CO)-C-12 VS (CNH)-C-13的质量差）的单电荷分子的信号差异，即含天冬氨酸/谷氨酸肽的第一个同位素信号与相应部分脱酰胺的天冬氨酸/谷氨酸衍生物的单同位素信号之间的质量差异。为了检测多肽内的部分脱酰胺，傅立叶变换离子回旋共振质谱法的优势已经被用来执行非常高的质量分辨率。在这项工作中，我们研究了直接输注电喷雾电离产生的三价离子。虽然特殊的外差检测模式比常规使用的宽带检测具有更高的质量分辨率，但通常只能调查一个小的质量窗口。使用宽带检测，我们能够分辨出m/z差为0.0064的离子，以检测酶或酸和碱条件下形成的部分脱酰胺肽。
Among the numerous forms of chemical degradation of peptides or proteins, deamidation is one of the alterations observed most frequently. In this irreversible reaction, a glutamine or an asparagine side chain is hydrolyzed to glutamic acid or aspartic acid, respectively (conversion of NH2 to OH). Besides its influence in the deterioration of biotechnological and food products, deamidation represents a defined posttranslational modification reaction with respect to proteomics. Here mass spectrometric techniques play a leading role in determining posttranslational modifications. However, not all mass spectrometers are able to resolve signal differences of 0.0193 Da (mass difference of (CO)-C-12 VS (CNH)-C-13) for singly charged molecules, the mass difference between the first isotopic signal of an asparagine/glutamine-containing peptide and the monoisotopic signal of the corresponding partially deamidated aspartate/glutamate derivative. To detect partial deamidation within peptides, advantage has been taken of the ability of Fourier transform ion cyclotron resonance mass spectrometry to perform very high mass resolution. In this work, we investigated up to triply charged ions produced by electrospray ionization using direct infusion. Although the special heterodyne detection mode enables higher mass resolution than the routinely used broadband detection, often only a small mass window can be investigated. Using broadband detection, we were able to resolve ions with a difference of m/z 0.0064 to detect partially deamidated peptides formed either enzymatically or under acidic and basic conditions.