Development of Sulfhydryl-Reactive Silica for Protein Immobilization in High-Performance Affinity Chromatography
作者:Rangan Mallik、Chunling Wa、David S. Hage
DOI:10.1021/ac061779j
日期:2007.2.1
Two techniques were developed for the immobilization of proteins and other ligands to silica through sulfhydryl groups. These methods made use of maleimide-activated silica (the SMCC method) or iodoacetyl-activated silica (the SIA method). The resulting supports were tested for use in high-performance affinity chromatography by employing human serum albumin (HSA) as a model protein. Studies with normal and iodoacetamide-modified HSA indicated that these methods had a high selectivity for sulfhydryl groups on this protein, which accounted for the coupling of 77−81% of this protein to maleimide- or iodoacetyl-activated silica. These supports were also evaluated in terms of their total protein content, binding capacity, specific activity, nonspecific binding, stability, and chiral selectivity for several test solutes. HSA columns prepared using maleimide-activated silica gave the best overall results for these properties when compared to HSA that had been immobilized to silica through the Schiff base method (i.e., an amine-based coupling technique). A key advantage of the supports developed in this work is that they offer the potential of giving greater site-selective immobilization and ligand activity than amine-based coupling methods. These features make these supports attractive in the development of protein columns for such applications as the study of biological interactions and chiral separations.
研究人员开发了两种通过巯基将蛋白质和其他配体固定在二氧化硅上的技术。这两种方法分别利用马来酰亚胺活化二氧化硅(SMCC法)和碘乙酰活化二氧化硅(SIA法)。研究人员用人血清白蛋白(HSA)作为模型蛋白,测试了所得载体在高效亲和色谱法中的使用效果。对正常和碘乙酰胺修饰HSA的研究表明,这两种方法对蛋白质上的巯基具有高度选择性,可将77-81%的蛋白质与马来酰亚胺或碘乙酰活化二氧化硅偶联。研究人员还评估了这些载体的总蛋白含量、结合能力、特异性活性、非特异性结合、稳定性以及对几种测试溶质的立体选择性。与通过席夫碱法(一种基于胺的偶联技术)固定在二氧化硅上的HSA相比,用马来酰亚胺活化二氧化硅制备的HSA柱在这些特性上具有最佳的整体效果。这项工作中开发的载体的一个关键优势在于,它们具有比基于胺的偶联方法更高的位点选择性固定和配体活性。这些特性使这些载体在开发蛋白质色谱柱方面具有吸引力,可用于生物相互作用和手性分离等应用。