Nanochemistry Research Institute, Department of Chemistry, Curtin University of Technology, Perth, Western Australia, Australia.
J Colloid Interface Sci. 2011 Nov 15;363(2):579-84. doi: 10.1016/j.jcis.2011.07.043. Epub 2011 Jul 22.
We have studied the structure of salt-free lysozyme at 293 K and pH 7.8 using molecular simulations and experimental SAXS effective potentials between proteins at three volume fractions, ϕ=0.012, 0.033, and 0.12. We found that the structure of lysozyme near physiological conditions strongly depends on the volume fraction of proteins. The studied lysozyme solutions are dominated by monomers only for ϕ≤0.012; for the strong dilution 70% of proteins are in a form of monomers. For ϕ=0.033 only 20% of proteins do not belong to a cluster. The clusters are mainly elongated. For ϕ=0.12 almost no individual particles exits, and branched, irregular clusters of large extent appear. Our simulation study provides new insight into the formation of equilibrium clusters in charged protein solutions near physiological conditions.
我们使用分子模拟和实验 SAXS 有效势研究了 293 K 和 pH 7.8 下无盐溶菌酶的结构，在三个体积分数ϕ=0.012、0.033 和 0.12 下研究了蛋白质之间的相互作用。我们发现，生理条件下溶菌酶的结构强烈依赖于蛋白质的体积分数。研究中溶菌酶溶液在ϕ≤0.012 时主要以单体为主；对于强稀释，70%的蛋白质以单体形式存在。对于ϕ=0.033，只有 20%的蛋白质不属于簇。这些簇主要是拉长的。对于ϕ=0.12，几乎没有单个粒子存在，而是出现了分支的、不规则的大程度的团簇。我们的模拟研究为生理条件下带电蛋白质溶液中平衡团簇的形成提供了新的见解。
