Department of Chemical and Materials Engineering, University of Cincinnati, Cincinnati, OH 45221-0012, USA.
J Chromatogr A. 2010 Mar 5;1217(10):1583-8. doi: 10.1016/j.chroma.2009.12.058. Epub 2010 Jan 4.
The adsorption of bovine serum albumin (BSA) and lysozyme (LYS) on siliceous SBA-15 with 24 nm pores was studied using flow microcalorimetry; this is the first attempt to understand the thermodynamics of protein adsorption on SBA-15 using flow microcalorimetry. The adsorption mechanism is a strong function of protein structure. Exothermic events were observed when protein-surface interactions were attractive. Entropy-driven endothermic events were also observed in some cases, resulting from lateral protein-protein interactions and conformational changes in the adsorbed protein. The magnitudes of the enthalpies of adsorption for primary protein-surface interactions decrease with increased surface coverage, indicating the possibility of increased repulsion between adsorbed protein molecules. Secondary exothermic events were observed for BSA adsorption, presumably due to secondary adsorption made possible by conformational changes in the soft BSA protein. These secondary adsorption events were not observed for lysozyme, which is structurally robust. The results of this study emphasize the influence of solution conditions and protein structure on conformational changes of the adsorbed protein and the value of calorimetry in understanding protein-surface interactions.
使用流动微量热法研究了牛血清白蛋白（BSA）和溶菌酶（LYS）在具有 24nm 孔径的硅质 SBA-15 上的吸附；这是首次尝试使用流动微量热法理解蛋白质在 SBA-15 上的吸附热力学。吸附机制是蛋白质结构的强函数。当蛋白质-表面相互作用具有吸引力时，会观察到放热事件。在某些情况下，还观察到熵驱动的吸热事件，这是由于吸附蛋白质中的侧向蛋白质-蛋白质相互作用和构象变化引起的。主要蛋白质-表面相互作用的吸附焓的大小随表面覆盖率的增加而降低，表明吸附蛋白质分子之间可能存在更大的排斥力。BSA 吸附时观察到二级放热事件，可能是由于软 BSA 蛋白质构象变化导致的二次吸附。这些二级吸附事件在结构坚固的溶菌酶中没有观察到。本研究的结果强调了溶液条件和蛋白质结构对吸附蛋白质构象变化的影响，以及量热法在理解蛋白质-表面相互作用方面的价值。
