Shores Kevin S, Udugamasooriya D Gomika, Kodadek Thomas, Knapp Daniel R
Department of Pharmacology and MUSC Proteomics Center, Medical University of South Carolina, Charleston, SC 29425, USA.
J Proteome Res. 2008 May;7(5):1922-31. doi: 10.1021/pr7006889. Epub 2008 Mar 22.
Biological samples can contain proteins with concentrations that span more than 10 orders of magnitude. Given the limited dynamic range of analysis methods, observation of proteins present at the lower concentrations requires depletion of high-abundance proteins, or other means of reducing the dynamic range of concentrations. Hexapeptide diversity library beads have been used to bind proteins in a complex sample up to a given saturation limit, effectively truncating the maximum concentration of proteins at a desired level. To avoid the potential problem of susceptibility of the hexapeptides to cleavage by proteases in the sample and/or bacterial degradation, peptide analogues that exhibit similar binding characteristics to peptides can be used in place of peptides. We report here the use of hexameric peptoid diversity library beads to reduce the dynamic range of protein concentrations in human cerebrospinal fluid (CSF). Using this method in conjunction with 2D LC/MS/MS analyses, we identified 200 unique proteins, about twice the number identified in untreated CSF.
生物样品中蛋白质的浓度范围可跨越超过10个数量级。鉴于分析方法的动态范围有限，要观察低浓度存在的蛋白质，就需要去除高丰度蛋白质，或采用其他方法来缩小浓度的动态范围。六肽多样性文库磁珠已被用于在复杂样品中结合蛋白质，直至达到给定的饱和极限，从而有效地将蛋白质的最大浓度截断在所需水平。为避免六肽易被样品中的蛋白酶裂解和/或细菌降解这一潜在问题，可使用与肽具有相似结合特性的肽类似物来替代肽。我们在此报告使用六聚体类肽多样性文库磁珠来缩小人类脑脊液（CSF）中蛋白质浓度的动态范围。将此方法与二维液相色谱/串联质谱分析相结合，我们鉴定出了200种独特的蛋白质，这一数量约为未处理脑脊液中鉴定出数量的两倍。
