Targeted particulate adhesion to cellulose surfaces mediated by bifunctional fusion proteins
Targeted particulate adhesion to cellulose surfaces mediated by bifunctional fusion proteins
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DOI：
10.1021/la700603u
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发表时间：
2007-10-09
期刊：
影响因子：
3.9
通讯作者：
Hammer, Daniel A.
中科院分区：
文献类型：
--
作者：
Pangu, Gautani;Johnston, Eric;Hammer, Daniel A.
颗粒对表面的粘附是许多商业和生物应用中不可或缺的要素。在这篇文章中，我们报告的直接测量蛋白质介导的沉积和结合的颗粒模型纤维素表面。该系统涉及特异性结合红色染料和纤维素的异型双功能融合蛋白家族。用红色染料标记胺包被的颗粒，并将融合蛋白以各种数量密度附着到这些颗粒上。使用微量移液管操作作为蛋白质的特异性及其表面密度和接触时间的函数，测量单个颗粒与纤维素纤维的粘附强度。在纤维实验中，发现粘附的频率和力随着接触时间的增加而增加。在受控流体动力学流动下，使用流动室探索了官能化颗粒与纤维素涂覆的载玻片的粘附动力学，所述流动室用于两种情况：结合颗粒的分离和悬浮液中颗粒的附着作为剪切速率和蛋白质的表面密度的函数。观察到高度特异性的粘附。颗粒分离的临界剪切速率是颗粒表面纤维素结合域（CBD）密度的增函数。在流动下观察到颗粒与纤维素的快速不可逆附着。使用一个二价蛋白质家族结合红色染料或纤维素，我们发现由于纤维素-CBD键的失效而发生颗粒分离。纤维结合和颗粒分离结果的比较表明，通过多种相互作用，可以用该分子系统获得高达2 nN的颗粒与纤维素的粘附力。这项研究，沿着目前正在开发的粘附模拟，形成了特定粘附应用的颗粒设计的基础。
The adhesion of particles to surfaces is an integral element in many commercial and biological applications. In this article, we report on the direct measurements of protein-mediated deposition and binding of particles to model cellulose surfaces. This system involves a family of heterobifunctional fusion proteins that bind specifically to both a red dye and cellulose. Amine-coated particles were labeled with a red dye, and a fusion protein was attached to these particles at various number densities. The strength of adhesion of a single particle to a cellulose fiber was measured using micropipette manipulation as a function of the specificity of the protein and its surface density and contact time. The frequency and force of adhesion were seen to increase with contact time in fiber experiments. The dynamics of adhesion of the functionalized particles to cellulose-coated glass slides under controlled hydrodynamic flow was explored using a flow chamber for two scenarios: detachment of bound particles and attachment of particles in suspension as a function of the shear rate and surface density of protein. Highly specific adhesion was observed. The critical shear rate for particle detachment was an increasing function of cellulose binding domain (CBD) density on particle surface. A rapid irreversible attachment of particles to cellulose was observed under flow. Using a family of proteins that were divalent for binding either the red dye or cellulose, we found that particle detachment occurred because of the failure of the cellulose-CBD bond. A comparison of fiber binding and particle detachment results suggests that forces of adhesion of particles to Cellulose of up to 2 nN can be obtained with this molecular system through multiple interactions. This study, along with the adhesion simulations currently under development, forms the basis of particulate design for specific adhesion applications.