Hybrid colloid analysis combining analytical ultracentrifugation and flow-field flow fractionation
Hybrid colloid analysis combining analytical ultracentrifugation and flow-field flow fractionation
复制标题
DOI：
10.1007/s00249-003-0319-6
复制
发表时间：
2003-08-01
影响因子：
2
通讯作者：
Völkel, A
中科院分区：
文献类型：
--
作者：
Cölfen, H;Völkel, A
铁蛋白（铁储存蛋白）是一种有机-无机杂化胶体，由空心蛋白质胶囊组成，其中充满了含有多达 4500 个铁原子的氢化铁。由于铁含量的变化和由此产生的密度差异，以及蛋白质寡聚化，粒度分布与密度分布叠加，使得通过分析超速离心对铁蛋白进行精确分析变得困难。本研究描述了如何将沉降系数分布的信息与流场流动分馏获得的扩散系数分布相结合，以产生混合物中低聚物的浮力摩尔质量，从而扩展了每种分析方法的信息内容。此外，沉降和扩散系数与简单的硬球聚集模型兼容，表明铁蛋白低聚物直至五聚物具有球状溶液结构。
Ferritin, the iron storage protein, is an organic-inorganic hybrid colloid consisting of a hollow protein capsule, which is filled with ferrihydride with up to 4500 iron atoms. Owing to the varying iron content and the resulting density differences, as well as the protein oligomerization, a particle size distribution is superimposed with a density distribution, making a precise analysis of ferritin by analytical ultracentrifugation difficult. This study describes how the information of the sedimentation coefficient distribution can be combined with the diffusion coefficient distribution obtained from flow-field flow fractionation to yield the buoyant molar mass of the oligomers in the mixture, extending the information content of each individual analytical method. In addition, the sedimentation and diffusion coefficients are compatible with a simple hard-sphere aggregation model, suggesting that the ferritin oligomers up to the pentamer have a globular solution structure.