Durand Nicolas F Y, Dellagiacoma Claudio, Goetschmann Raphaël, Bertsch Arnaud, Märki Iwan, Lasser Theo, Renaud Philippe
Microsystems Laboratory, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.
Anal Chem. 2009 Jul 1;81(13):5407-12. doi: 10.1021/ac900617b.
The diffusion of charged proteins in liquid-filled nanometer-sized apertures with charged surfaces has been investigated with fluorescence correlation spectroscopy (FCS). Based on a two-dimensional (2D) multicomponent diffusion model, key parameters such as the number of molecules diffusing freely inside the nanochannel or interacting with the surfaces, together with the specific diffusion parameters, could be extracted. Different regimes of diffusion have been observed and described by a model, which takes into account the steric exclusion, the reversible surface adsorption of the biomolecules, and the exclusion-enrichment effect that is due to the charge of the proteins and the ionic strength of the solution. Conditions where the diffusion of proteins through nanoconfined spaces can be of the same magnitude as in the bulk were both predicted and experimentally verified.
利用荧光相关光谱法（FCS）研究了带电荷的蛋白质在具有带电表面的充满液体的纳米尺寸孔中的扩散情况。基于二维（2D）多组分扩散模型，可以提取诸如在纳米通道内自由扩散或与表面相互作用的分子数量等关键参数，以及特定的扩散参数。通过一个模型观察并描述了不同的扩散状态，该模型考虑了空间排斥、生物分子的可逆表面吸附以及由于蛋白质电荷和溶液离子强度引起的排斥富集效应。预测并通过实验验证了蛋白质在纳米受限空间中的扩散与在本体中扩散具有相同量级的条件。
