Department of Biochemistry and Molecular Biology, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, 3010 Australia.
Proteome Sci. 2011 Jan 17;9(1):2. doi: 10.1186/1477-5956-9-2.
We describe a method to identify metabolites of proteins that eliminates endogenous background by using stable isotope labeled matrices. This technique allows selective screening of the intact therapeutic molecule and all metabolites using a modified precursor ion scan that monitors low molecular weight fragment ions produced during MS/MS. This distinct set of low mass ions differs between isotopically labeled and natural isotope containing species allowing excellent discrimination between endogenous compounds and target analytes. All compounds containing amino acids that consist of naturally abundant isotopes can be selected using this scanning technique for further analysis, including metabolites of the parent molecule. The sensitivity and selectivity of this technique is discussed with specific examples of insulin metabolites identified within a complex matrix using a range of different validated low mass target ions.
我们描述了一种通过使用稳定同位素标记的基质来识别蛋白质代谢物的方法，该方法可以消除内源性背景。该技术允许使用改良的前体离子扫描选择性筛选完整的治疗分子和所有代谢物，该扫描监测在 MS/MS 过程中产生的低分子量片段离子。在稳定同位素标记和天然同位素存在的物种之间，这种独特的低质量离子集合不同，允许在内源性化合物和目标分析物之间进行极好的区分。可以使用该扫描技术选择包含由天然丰度同位素组成的氨基酸的所有化合物，以进行进一步分析，包括母体分子的代谢物。讨论了该技术的灵敏度和选择性，并使用一系列不同验证的低质量靶离子在复杂基质中鉴定胰岛素代谢物的具体实例进行了说明。
