Smart Core-Shell Microgel Support for Acetyl Coenzyme A Synthetase: A Step Toward Efficient Synthesis of Polyketide-Based Drugs

摘要

The flexibility in tuning the structure and charge properties of PNIPAm microgels during their synthesis makes them a suitable choice for various biological applications. Two-step free radical polymerization, a common method employed for synthesis of core—shell microgel has been well adopted to obtain cationic poly(N-isopropylacry-lamide-aminoethyl metnacrylate) (PNIPAm-AEMA) shell and PNIPAm core. Scanning electron microscopy (SEM), dynamic light scattering (DLS), zeta potential, and nirihydrin assay suggests nearly monodispersed particles; qf cationic, nature. Amino groups on the microgel provides suitable attachment point for covalent immobilization of acetyl coenzyme A synthetase (Acs) via l-ethyl-3-(3-N,N- dimethylaminopropyl) carbodiimide (EDC) chemistry. On immobilization, 61.55% of initial activity of Acs has been; retained, while Michaelis-Menten kinetics of the immobilized Acs indicates identical K_m (Michaelis constant) but decrease in the V_(max) (maximum substrate conversion rate) compared to free enzyme. Immobilized Acs shows an improvement in activity at wide temperature and pH range and also demonstrates good; thermal, storage, and operational stability. The Acs—microgel bioconjugate has been successfully reused for four consecutive operation cycles with more than 50% initial activity.