亮氨酸脑啡肽一级结构的电喷雾质谱分析

Determination of first-order structure of leucine enkephalin by electrospray ionization mass spectrum

目的:测定亮氨酸脑啡肽的精确相对分子质量及其一级结构。方法:应用高分辨电喷雾质谱法及碰撞活化解离技术对亮氨酸脑啡肽进行测定,根据典型的碎片离子确证其氨基酸序列及精确相对分子质量。结果:测得亮氨酸脑啡肽的准分子离子峰[M+H]+m/z556.2773,[M+Na]+m/z578.2587,与理论值相符合。通过适当调整碰撞解离电压,得到一系列典型的y离子、b离子及部分碎片离子,进而确证亮氨酸脑啡肽的完整序列。结论:该方法简单,快速,实用,测试成本低。

Aim： To determine the exact relative molecular weight and the first-order structure of leucine enkephalin. MethodS：The exact relative molecular weight and amino acid sequence of leucine enkephalin were determined by HR-ESI mass spectrometry; a series of typical fragment ions were obtained by collision-activated dissociation （CAD）. Results： The quasi-molecular ions of leucine enkephalin were 556. 277 3 [ M ＋ H ] ＋ and 578. 258 7 [ M ＋ Na] ＋ ,which was consistent with the theoretical value of leucine enkephalin＇s relative molecular weight. The y and b series of fragment ions were obtained by adjusting the fragmental voltage, and the sequence of leucine enkephalin was confirmed. Conclusion： The method is simple, quick and practical with low price.