Rahman Monica S, Chandrarathne Bhagya, Bender Katie, Hinkle Jasmine, Page Richard C, Konkolewicz Dominik
Department of Chemistry and Biochemistry, Miami University, 651 E High Street, Oxford, Ohio 45056, United States.
Biomacromolecules. 2025 Jul 14;26(7):4209-4218. doi: 10.1021/acs.biomac.5c00212. Epub 2025 Jun 6.
Stimuli-responsive bioconjugates are developed to control enzymatic activity and stability using a pH-responsive polymer based on ,-dimethyl aminopropylacrylamide. Prior work has shown that conjugating -isopropylacrylamide (NIPAm) polymer to the lipase B (CalB) enzyme has an inhibitory effect. Due to the similar hydrophobicity to the substrate of CalB, NIPAm polymer may block the enzyme's catalytic site, thereby inhibiting the enzyme's activity. This study shows that conjugating pDMAPA DP40--NIPAm DP10 to CalB has a pH-responsive effect on the catalytic property of CalB, with inverse stability responses. At low pH, where the polymer is extended, high activity is observed, while at low pH, the inhibitory block binds or occludes the active site and increases stability. A similar approach used a known inhibitor, -acryloyl-d-glucosamine (AGA), for lysozyme. Conjugating pDMAPA DP40--AGA DP10 elicited a similar pH-controlled stability-activity response in lysozyme. Therefore, we propose that the polymer's pH-dependent interaction with protein can effectively regulate the protein between a highly active state and high stability behavior.
开发了刺激响应性生物共轭物，以使用基于N，N-二甲基氨基丙基丙烯酰胺的pH响应聚合物来控制酶活性和稳定性。先前的研究表明，将聚N-异丙基丙烯酰胺（NIPAm）聚合物与脂肪酶B（CalB）酶共轭具有抑制作用。由于NIPAm聚合物与CalB的底物具有相似的疏水性，它可能会阻断酶的催化位点，从而抑制酶的活性。本研究表明，将pDMAPA DP40-NIPAm DP10与CalB共轭对CalB的催化性能具有pH响应效应，且稳定性响应相反。在低pH值下，聚合物伸展，观察到高活性，而在高pH值下，抑制性阻断结合或封闭活性位点并增加稳定性。类似的方法使用已知的抑制剂N-丙烯酰基-D-葡萄糖胺（AGA）作用于溶菌酶。将pDMAPA DP40-AGA DP10共轭在溶菌酶中引发了类似的pH控制的稳定性-活性响应。因此，我们提出聚合物与蛋白质的pH依赖性相互作用可以有效地在高活性状态和高稳定性行为之间调节蛋白质。
