Carmali Sheiliza, Murata Hironobu, Amemiya Erika, Matyjaszewski Krzysztof, Russell Alan J
Center for Polymer-Based Protein Engineering and ‡Department of Chemical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213, United States.
Center for Polymer-Based Protein Engineering and Department of Chemical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213, United States.
ACS Biomater Sci Eng. 2017 Sep 11;3(9):2086-2097. doi: 10.1021/acsbiomaterials.7b00281. Epub 2017 Aug 3.
The growth of polymers from the surface of proteins via controlled radical polymerization depends on the attachment of small molecule initiators to amino acid residues. Our ability to control and harness the power of polymer-based protein engineering is reliant on the accuracy of prediction where and how fast atom transfer radical polymerization (ATRP) initiators will react with a protein surface. We performed a systematic characterization of the reaction between a bromine-functionalized -hydroxysuccinimide amine-reactive ATRP initiator and the amino groups in lysozyme and chymotrypsin. The tertiary structures of the proteins were used to predict computationally α-amino group and lysine side-chain accessibility and analyze the chemical and structural environment of the amino groups. To predict reactivity from accessibility calculations, a probe radius that resembled the size of the initiator molecule was used. Experimental data showed that the rate of initiator-protein modification at each amine site was related to surface accessibility but not the p of amino groups. Further refinements of the prediction of where the initiator modified the protein and in what sequence were achieved by considering the local environment of each amino group.
通过可控自由基聚合在蛋白质表面生长聚合物取决于小分子引发剂与氨基酸残基的连接。我们控制和利用基于聚合物的蛋白质工程能力的关键在于预测原子转移自由基聚合（ATRP）引发剂与蛋白质表面反应的位置和速度的准确性。我们对溴功能化的N-羟基琥珀酰亚胺胺反应性ATRP引发剂与溶菌酶和胰凝乳蛋白酶中的氨基之间的反应进行了系统表征。利用蛋白质的三级结构通过计算预测α-氨基和赖氨酸侧链的可及性，并分析氨基的化学和结构环境。为了根据可及性计算预测反应性，使用了与引发剂分子大小相似的探针半径。实验数据表明，每个胺位点上引发剂-蛋白质修饰的速率与表面可及性有关，而与氨基的pKa无关。通过考虑每个氨基的局部环境，对引发剂修饰蛋白质的位置和顺序的预测进行了进一步优化。
