Alberta Ingenuity Centre for Carbohydrate Science and Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2.
Anal Chem. 2011 Jul 1;83(13):5160-7. doi: 10.1021/ac200244u. Epub 2011 Jun 14.
A simple method for establishing whether complexes composed of small molecules detected by electrospray ionization mass spectrometry (ES-MS) originate from specific interactions in solution or nonspecific binding during the ES process is described. The technique, referred to as the nonspecific probe method, exploits the tendency of small molecules to bind nonspecifically to macromolecules during the ES process to establish the presence of specific noncovalent interactions. To implement the method, a macromolecule probe (P(NS)), which does not bind specifically to any of the components present in solution, is added prior to ES-MS analysis. The existence of specific small-molecule complexes is determined from an analysis of the measured distributions of the small molecules bound nonspecifically to P(NS). The principal assumption on which this methodology is based is that nonspecific binding of small molecules and their complexes to P(NS) during ES is a statistical (random) process. A mathematical framework for establishing the presence of specific heterocomplexes is presented. The reliability of the method for distinguishing specific from nonspecific small-molecule interactions is illustrated for peptide-antibiotic and metal ion-ligand interactions in water.
一种简单的方法，用于确定通过电喷雾电离质谱（ES-MS）检测到的小分子复合物是否源自溶液中的特定相互作用或 ES 过程中的非特异性结合。该技术称为非特异性探针方法，利用小分子在 ES 过程中与大分子非特异性结合的趋势来建立特定非共价相互作用的存在。为了实施该方法，在 ES-MS 分析之前添加一种不与溶液中存在的任何成分特异性结合的大分子探针（P(NS)）。通过分析非特异性结合到 P(NS)上的小分子的测量分布，可以确定特定小分子复合物的存在。该方法学基于的主要假设是，小分子及其复合物在 ES 期间与 P(NS)的非特异性结合是一个统计（随机）过程。提出了一种用于确定特定杂合复合物存在的数学框架。该方法用于区分特定和非特异性小分子相互作用的可靠性在水中的肽-抗生素和金属离子-配体相互作用中得到了说明。
