USE OF 18O LABELS TO MONITOR DEAMIDATION DURING SAMPLE PROCESSING

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 在样品处理过程中，尤其是在使用典型的胰酶消化方案时，可能会出现脱酰胺现象。我们已经开发了一种18O标记方法来监控这些人工脱酰胺，其中酶消化是在18O标记的水中进行的。在体内，由于-NH_2基团被-OH基团取代，每个脱酰胺基的质量位移为1Da，而在消化过程中发生的质量位移为3Da，额外的2Da是由于掺入一个18O原子而产生的。这项研究最近(Li等人，2008)发表在《美国质谱学学会杂志》上，2008，19,855-864。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Deamidation may occur as an artifact during sample processing, particularly when using typical tryptic digestion protocols. We have developed an 18O labeling approach to monitor these artificial deamidations, where the enzymatic digestion was carried out in 18O labeled water. While in vivo deamidation causes a +1 Da mass shift per deamidation site due to the substitution of the -NH2 group by the -OH group, those occurred during digestion lead to a +3 Da mass shift, with the extra +2 Da arising from the incorporation of one 18O atom. This study has recently been published (Li et al., 2008) in the Journal of the American Society for Mass Spectrometry, 2008, 19, 855-864.