磷酸化肽富集的方法--使用高亲和力固相萃取μElution板

The reversible phosphorylation of serine, threonine and tyrosine, is one of the most important post-translational modifications involved in various cellular functions. Identification of phosphorylation sites by mass spectrometry is challenging due to the low abundance of phosphopeptides and their limited ionization efficiency. Therefore, it is critical to selectively enrich the phosphopeptides prior to MS analysis. In this study we illustrate the use of a Phosphopeptide Enrichment Kit that consists of an affinity extraction µElution plate, and a unique chemical reagent under the trade name of Enhancer, which is shown to improve the selectivity of the affinity solid-phase extraction (SPE) towards phosphopeptides for highly complex bio­logical samples. Also, a vial of phosphopeptide standard is included in the kit as a control sample to validate the affinity extraction method. MALDI-TOF MS and nano-scale LC/MS were used to evaluate the per­formance of the affinity solid-phase extraction device. Recommended protocol for the affinity SPE µElution plate, and sample preparation for MS analysis are included in the application.