An industrially important enzyme, Candida antarctica lipase B (CalB), was modified with a range of functional polymers including hydrophilic, hydrophobic, anionic, and cationic character using a “grafting to” approach. We determined the impact of polymer chain length on CalB activity by synthesizing biohybrids of CalB with each polymer at three different chain lengths, using reversible addition-fragmentation chain transfer (RAFT) polymerization. The activity of CalB in both aqueous and aqueous-organic media mixtures was significantly enhanced for acrylamide (Am) and N,N-dimethyl acrylamide (DMAm) conjugates, with activity remaining approximately constant in 25 and 50% ethanol solvent systems. Interestingly, the activity of N,N-dimethylaminopropyl-acrylamide (DMAPA) conjugates increased gradually with increasing organic solvent content in the system. Contrary to other literature reports, our study showed significantly diminished activity for hydrophobic polymer-protein conjugates. Functional thermal stability assays also displayed a considerable enhancement of retained activity of Am, DMAm, and DMAPA conjugates compared to the native CalB enzyme. Thus, this study provides an insight into possible advances in lipase production, which can lead to new improved lipase bioconjugates with increased activity and stability.

中文翻译：

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脂肪酶的聚合物修饰，底物相互作用和潜在的抑制作用

一种工业上重要的酶，南极假丝酵母脂肪酶B（CalB），通过“接枝”方法用一系列功能性聚合物进行了修饰，包括亲水，疏水，阴离子和阳离子特性。通过使用可逆加成-断裂链转移（RAFT）聚合反应，通过在三种不同链长下与每种聚合物合成CalB的生物杂化物，我们确定了聚合物链长对CalB活性的影响。对于丙烯酰胺（Am）和N，N-二甲基丙烯酰胺（DMAm）共轭物，CalB在水性和水性有机介质混合物中的活性均得到显着提高，在25％和50％的乙醇溶剂体系中，该活性几乎保持恒定。有趣的是，活性Ñ，N-二甲基氨基丙基-丙烯酰胺（DMAPA）共轭物随着体系中有机溶剂含量的增加而逐渐增加。与其他文献报道相反，我们的研究表明，疏水性聚合物-蛋白质缀合物的活性大大降低。与天然CalB酶相比，功能热稳定性测定还显示出Am，DMAm和DMAPA缀合物的保留活性的显着提高。因此，该研究提供了对脂肪酶生产中可能的进展的见识，其可以导致新的改进的脂肪酶生物缀合物具有增加的活性和稳定性。