Department of Biological Sciences , Carnegie Mellon University , 4400 Fifth Avenue , Pittsburgh , Pennsylvania 15213 , United States.
Center for Polymer-Based Protein Engineering , Carnegie Mellon University , 5000 Forbes Avenue , Pittsburgh , Pennsylvania 15213 , United States.
Biomacromolecules. 2019 Mar 11;20(3):1235-1245. doi: 10.1021/acs.biomac.8b01651. Epub 2019 Feb 4.
The molecular sieving properties of protein surface-attached polymers are the central features in how polymers extend therapeutic protein lifetimes in vivo. Yet, even after 30 years of research, permeation rates of molecules through polymer-surrounded protein surfaces are largely unknown. As a result, the generation of protein-polymer conjugates remains a stochastic process, unfacilitated by knowledge of structure-function-polymer architecture relationships. In this work, polymers are grown from the surface of avidin using atom transfer radical polymerization (ATRP) and used to determine how polymer length and density influence the binding kinetics of ligands as a function of ligand size and shape. The rate of binding is strongly dependent on the grafting density of polymers and the size of the ligand but interestingly, far less dependent on the length of the polymer. This study unveils a deeper understanding of relationship between polymer characteristics and binding kinetics, discovering important steps in rational design of protein-polymer conjugates.
蛋白质表面附着聚合物的分子筛特性是聚合物如何延长治疗性蛋白质在体内寿命的核心特征。然而，即使经过 30 年的研究，分子通过聚合物包围的蛋白质表面的渗透速率在很大程度上仍然未知。因此，蛋白质-聚合物缀合物的产生仍然是一个随机过程，由于缺乏结构-功能-聚合物结构关系的知识，无法得到促进。在这项工作中，使用原子转移自由基聚合（ATRP）从亲和素表面生长聚合物，并用于确定聚合物长度和密度如何影响配体的结合动力学，作为配体大小和形状的函数。结合速率强烈依赖于聚合物的接枝密度和配体的大小，但有趣的是，对聚合物长度的依赖性要小得多。这项研究揭示了聚合物特性和结合动力学之间关系的更深入理解，为蛋白质-聚合物缀合物的合理设计发现了重要步骤。
