Determination of
<i>N</i>
‐terminal myristoylation of proteins using a combined gas chromatographic/mass spectrometric assay of derived myristoylglycine: Electron impact‐induced fragmentation of acylglycine derivatives
作者:R. A. Jeffrey McIlhinney、David J. Harvey
DOI:10.1002/jms.1190300616
日期:1995.6
A method based on gas chromatography/mass spectrometry is described for the detection of N-terminal myristoylation of proteins. Myristoylglycine, derivatized as its trimethylsily (TMS) ester, gave an electron impact mass spectrum containing abundant molecular and and [M CH3]+ ions, together with several ions diagnostic of the acyl glycine moiety, namely at m/z 145, 158, 172 and 189. The compositions of these ions and the mechanisms that produced them were investigated by high-resolution mass measurements, deuterium labelling and the preparation of analogous compounds. As these were present in the spectra of all acylglycines examined, they could be used as markers for these compounds. A selected-ion monitoring method for the detection of myristoylglycine was set up using the above ions and was used to confirm the presence of N-terminal myristoylation in three reference peptides. A series of ions produced by radical-induced cleavage of the alkyl chain following TMS group migration and elimination of carbon dioxide gave information on the structure of the chain and could be used to determine the structure of other potential acylglycines such as those with unsaturated acyl chains. Thus the derivatives could be used not only to detect myristoylation of protein, but also to detect and determine the structures of other acyl substituents.
基于气相色谱/质谱法的一种方法用于检测蛋白质的N-端豆蔻酰化。豆蔻酰甘氨酸经过三甲基硅烷(TMS)酯化后,其电子撞击质谱含有丰富的分子离子和[M-CH3]+离子,以及几个能诊断酰基甘氨酸部分特征的离子,即m/z在145、158、172和189处的离子。通过对这些离子的组成及产生机制进行高分辨质量测量、氘标记和类似化合物的制备来加以研究。由于这些离子在所有检测的酰基甘氨酸谱图中均存在,因此可以作为这些化合物的标志。利用上述离子建立了一种选择离子监测方法用于检测豆蔻酰甘氨酸,并用于确认三种参比肽中N-端豆蔻酰化的存在。通过TMS基团迁移和二氧化碳消除后烷基链的自由基诱导断裂产生的一系列离子,提供了有关链结构的信息,并可用于确定包括含不饱和酰基链在内的其他潜在酰基甘氨酸的结构。因此,这些衍生物不仅可以用于检测蛋白质的豆蔻酰化,还可以用于检测和确定其他酰基取代基的结构。