Harriman S P, Hill J A, Tannenbaum S R, Wishnok J S
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, USA.
J Am Soc Mass Spectrom. 1998 Mar;9(3):202-7. doi: 10.1016/S1044-0305(97)00252-3.
Nanoelectrospray (nanoES) tandem mass spectrometry was used to examine covalently modified peptides in crude enzymatic digests of human serum albumin (HSA) that had been exposed to either benzo[a]pyrene diol epoxide (B[a]PDE, 1), chrysene diol epoxide (CDE, 2), 5-methylchrysene diol epoxide (5MeCDE, 3), or benzo[g]chrysene diol epoxide (B[g]CDE, 4). The low flow rates of nanoES (approximately 20 nL/min) allowed several MS/MS experiments to be optimized and performed on a single sample with very little sample consumption (approximately 30 min analysis time/microL sample). Initially, nanoES was compared with conventional LC/MS/MS analysis of carcinogen-peptide adducts. For example, nanoES analysis of an unseparated digest of B[a]PDE-treated serum albumin revealed the same peptides (RRHPY and RRHPY-FYAPE) that were previously shown, by LC/MS/MS, to be adducted with B[a]PDE. In addition, nanoES could detect unstable peptide adducts that might not otherwise have been directly observable. Finally, nanoES was shown to be an effective way to screen mixtures of modified and unmodified peptides for which no chromatographic information is available.
采用纳米电喷雾（nanoES）串联质谱法检测人血清白蛋白（HSA）粗酶解物中的共价修饰肽段，该粗酶解物已暴露于苯并[a]芘二醇环氧化物（B[a]PDE，1）、二氢苊二醇环氧化物（CDE，2）、5-甲基二氢苊二醇环氧化物（5MeCDE，3）或苯并[g]二氢苊二醇环氧化物（B[g]CDE，4）中。纳米电喷雾的低流速（约20 nL/min）使得可以在极少的样品消耗情况下（约30分钟分析时间/微升样品）对单个样品优化并进行多次串联质谱实验。最初，将纳米电喷雾与致癌物 - 肽加合物的传统液相色谱/串联质谱分析进行了比较。例如，对经B[a]PDE处理的血清白蛋白未分离酶解物进行纳米电喷雾分析，揭示了与之前液相色谱/串联质谱分析中显示的相同肽段（RRHPY和RRHPY - FYAPE），这些肽段与B[a]PDE形成了加合物。此外，纳米电喷雾能够检测到可能无法直接观察到的不稳定肽加合物。最后，纳米电喷雾被证明是一种筛选没有色谱信息的修饰和未修饰肽混合物的有效方法。
