Department of Chemistry and Biochemistry, Southern Illinois University at Carbondale, Carbondale, IL 62901, USA.
Anal Biochem. 2010 May 1;400(1):56-60. doi: 10.1016/j.ab.2010.01.009. Epub 2010 Jan 13.
Previous studies in our group have shown that the analyte signal in a matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) experiment is strongly influenced by the binding interactions between the target surface and the analyte. Specifically, the analyte signal increases with decreases in surface binding affinity, which has been attributed to more unbound analyte being available for incorporation within the MALDI matrix. In this work, polyethylene glycol (PEG) was chemically grafted onto a polyurethane (PU) film to produce a MALDI target having reduced surface-protein binding affinity, and the effect of this modification on protein MALDI ion signals was investigated. The proteins myoglobin, lysozyme, and albumin were used to evaluate the PEG PU modified target as compared with a PU target and a commercial stainless steel target. It is shown that there are enhancements in the protein MALDI ion signals on the PEG PU modified target and that the limit of detection for these proteins is decreased by a factor of 2 to 6 in comparison with the unmodified PU and the commercial stainless steel targets.
先前我们小组的研究表明，基质辅助激光解吸/电离质谱（MALDI MS）实验中的分析物信号强烈受到目标表面与分析物之间结合相互作用的影响。具体而言，分析物信号随表面结合亲和力的降低而增加，这归因于更多未结合的分析物可用于掺入 MALDI 基质中。在这项工作中，将聚乙二醇（PEG）化学接枝到聚氨酯（PU）薄膜上，以产生具有降低的表面蛋白结合亲和力的 MALDI 靶，并且研究了这种修饰对蛋白质 MALDI 离子信号的影响。使用肌红蛋白、溶菌酶和白蛋白来评估与 PU 靶和商业不锈钢靶相比，PEG PU 修饰的靶对蛋白质 MALDI 离子信号的影响。结果表明，在 PEG PU 修饰的靶上，蛋白质 MALDI 离子信号增强，并且与未修饰的 PU 和商业不锈钢靶相比，这些蛋白质的检测限降低了 2 到 6 倍。
