Probing Adenosine Nucleotide-Binding Proteins with an Affinity-Labeled Nucleotide Probe and Mass Spectrometry
作者:Haibo Qiu、Yinsheng Wang
DOI:10.1021/ac0622375
日期:2007.8.1
Mass spectrometry combined with chemical labeling strategies has become very important in biological analysis. Herein, we described the application of a biotin-conjugated acyl nucleotide for probing adenosine nucleotide-binding proteins. We demonstrated that the probe reacted specifically with the lysine residue at the nucleotide-binding site of two purified adenosine nucleotide-binding proteins, Escherichia coli recombinase A (RecA) and Saccharomyces cerevisiae alcohol dehydrogenase-I (YADH-I). A single conjugate peptide with a specifically labeled lysine residue was identified, by using LC−MS/MS, from the tryptic digestion mixture of the reaction products of the nucleotide analogue with RecA or YADH-I. The strategy, which involved labeling reaction, enzymatic digestion, affinity purification, and LC−MS/MS analysis, was relatively simple, fast, and straightforward. The method should be generally applicable for the identification of lysine residues at the nucleotide-binding site of other proteins. The biotin-conjugated acyl nucleotide probe also allowed for the enrichment and identification of nucleotide-binding proteins from complex protein mixtures; we showed that more than 50 adenosine nucleotide-binding proteins could be identified from the whole-cell lysates of HeLa-S3 and WM-266-4 cells.
质谱结合化学标记策略在生物分析中变得非常重要。本文中,我们描述了一种生物素化的酰基核苷酸探针在探测腺苷核苷酸结合蛋白中的应用。我们证明了该探针特异性地与两种纯化的腺苷核苷酸结合蛋白——大肠杆菌重组酶A(RecA)和酵母酒精脱氢酶I(YADH-I)的核苷酸结合位点的赖氨酸残基反应。通过LC-MS/MS,从核苷酸类似物与RecA或YADH-I反应产物的胰蛋白酶消化混合物中鉴定出一个带有特异性标记赖氨酸残基的单一偶联肽。该策略包括标记反应、酶消化、亲和纯化和LC-MS/MS分析,相对简单、快速且直接。该方法应普遍适用于鉴定其他蛋白质核苷酸结合位点的赖氨酸残基。生物素化的酰基核苷酸探针还允许从复杂蛋白混合物中富集和鉴定核苷酸结合蛋白;我们展示了从HeLa-S3和WM-266-4细胞的全细胞裂解物中可以鉴定出超过50种腺苷核苷酸结合蛋白。