Hua ZhenDong, Chen Zhiyong, Li YuanZong, Zhao MeiPing
Beijing National Laboratory for Molecular Sciences, The Key Laboratory of Bioorganic Chemistry & Molecular Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Langmuir. 2008 Jun 3;24(11):5773-80. doi: 10.1021/la703963f. Epub 2008 May 7.
A novel stimuli-responsive protein imprinted polymer for selective recognition of bovine serum albumin is presented. N-[3-(Dimethylamino)propyl]-methacrylamide, which is positively charged in neutral solution and is able to self-assemble onto the template protein through electrostatic interaction, was chosen as the functional monomer. Polymerization was carried out in the presence of N-isopropylacrylamide as an assistant monomer, which resulted in a stimuli-responsive protein imprinted polymer. The template proteins were easily removed by treatment with 500 mmol L(-1) NaCl solution. The influences of the external stimuli, such as temperature and ionic strength, on the polymer affinity were investigated, and a clear conformational memory was observed. The association constant ( Ka) and binding capacity ( Qmax) for the specific interaction between the protein imprinted polymer and the template protein were determined by Scatchard plots and found to be 9.6 x 10(4) L mol(-1) and 4.7 micromol g(-1), respectively. Several proteins different in molecular weight and isoelectric point were employed as reference, and it was shown that the charge effect and the shape memory effect were the major factors affecting the imprint formation and template recognition. Finally, this imprinted polymer was used to purify the bovine serum albumin from the protein mixture and real sample, which demonstrated its high selectivity.
本文介绍了一种用于选择性识别牛血清白蛋白的新型刺激响应性蛋白质印迹聚合物。选择在中性溶液中带正电荷且能够通过静电相互作用自组装到模板蛋白上的N-[3-(二甲基氨基)丙基]-甲基丙烯酰胺作为功能单体。在N-异丙基丙烯酰胺作为辅助单体存在的情况下进行聚合反应，得到一种刺激响应性蛋白质印迹聚合物。通过用500 mmol L(-1) NaCl溶液处理可轻松去除模板蛋白。研究了温度和离子强度等外部刺激对聚合物亲和力的影响，并观察到明显的构象记忆。通过Scatchard图确定蛋白质印迹聚合物与模板蛋白之间特异性相互作用的缔合常数(Ka)和结合容量(Qmax)，分别为9.6 x 10(4) L mol(-1)和4.7 μmol g(-1)。使用几种分子量和等电点不同的蛋白质作为参考，结果表明电荷效应和形状记忆效应是影响印迹形成和模板识别的主要因素。最后，这种印迹聚合物用于从蛋白质混合物和实际样品中纯化牛血清白蛋白，证明了其高选择性。
