Diffusion of Proteins across Silica Colloidal Crystals
Diffusion of Proteins across Silica Colloidal Crystals
复制标题
DOI：
10.1021/acs.langmuir.8b01261
复制
发表时间：
2018-09-04
期刊：
影响因子：
3.9
通讯作者：
Zharov, Ilya
中科院分区：
文献类型：
--
作者：
Ignacio-de Leon, Patricia Anne A.;Eygeris, Yulia;Zharov, Ilya
我们研究了溶菌酶（Lz）、牛血红蛋白（BHb）和牛血清白蛋白（BSA）三种模型蛋白的扩散，它们垂直于烧结二氧化硅胶体晶体的（111）面，具有三种不同的孔“半径”（7.5、19和27 nm）。我们证明，当纳米孔足够小（7.5和19纳米）时，这些胶体晶体表现出尺寸选择性。由于这些纳米孔仍然比扩散的蛋白质大，因此观察到的尺寸选择性可以归因于胶体纳米孔的弯曲性。较大的（27 nm）纳米孔导致更高的传输速率，但以选择性为代价。除了尺寸选择性外，我们还证明了19 nm纳米孔对相当分子量的蛋白质具有形状选择性。我们发现，制备烧结胶体晶体所需的高温烧结降低了蛋白质和纳米孔表面之间的相互作用程度，这在扩散中似乎起着次要作用，并且运输选择性仅由蛋白质的大小和形状决定。综上所述，我们的观察结果表明，烧结二氧化硅胶体晶体具有易于控制的孔径、尺寸和形状选择性以及最小的表面污垢，是很有希望用于蛋白质分离的纳米孔膜。
We studied the diffusion of three model proteins, lysozyme (Lz), bovine hemoglobin (BHb), and bovine serum albumin (BSA), normal to the (111) plane of sintered silica colloidal crystals with three different pore "radii" (7.5, 19, and 27 nm). We demonstrated that these colloidal crystals exhibit size selectivity when the nanopores are sufficiently small (7.5 and 19 nm). Because these nanopores are still larger than the diffusing proteins, the observed size selectivity can be attributed to the tortuosity of the colloidal nanopores. Larger (27 nm) nanopores led to higher transport rates but at the cost of selectivity. In addition to the size selectivity, we also demonstrated that 19 nm nanopores possess shape selectivity for the proteins of comparable molecular weights. We showed that the high temperature sintering required for the preparation of sintered colloidal crystals reduces the extent of interactions between the proteins and the nanopore surface, which appear to play a minor role in the diffusion, and that transport selectivity is decided solely by protein size and shape. Taken together, our observations suggest that sintered silica colloidal crystals constitute promising nanoporous membranes for protein separations, with easily controllable pore size, size and shape selectivity, and minimal surface fouling.