Facile synthesis of glucoamylase embedded metal-organic frameworks (glucoamylase-MOF) with enhanced stability

•Glucoamylase-MOFs was prepared by simple, facile and efficient one pot method within 20 min.•The prepared glucoamylase MOFs was characterized by using FT-IR, confocal microscopy, XRD and SEM.•Improved thermal stability of glucoamylase-MOF was expressed as half-life & deactivation energy.•Reusability and storage stability was investigated to determine its industrial applicability.•Conformational changes in glucoamylase-MOFs were evaluated by FT-IR spectroscopy tools.

The self-assembled glucoamylase metal-organic framework (glucoamylase-MOF) was synthesized by facile one-step method within 20 min by simply mixing aqueous solution of 2-methylimidazole (160 mM), glucoamylase (5 mg/mL) and zinc acetate (40 mM) at room temperature (28 ± 2 °C). The prepared glucoamylase-MOF was characterized by using FT-IR, confocal scanning laser microscopy, XRD and SEM. The robustness and thermal stability of glucoamylase embedded MOF was evaluated in terms of half-life (in the range of 60-80 °C) which showed 6 folds increment as against free form. Further, in Michaelis-Menten kinetics studies, glucoamylase entrapped MOF exhibited higher Km value and lower Vmax value as compared to native enzyme. Moreover, the immobilized glucoamylase exhibited up to 57% of residual activity after six consecutive cycles of reuse, whereas it retained 91% of residual activity till 25 days of storage. Finally, the conformational changes occurred after the encapsulation of glucoamylase in the interior of MOF, which was analyzed by using FT-IR data analysis tools.

Graphical abstractA facile and highly efficient one pot synthesis method of glucoamylase embedded MOF was prepared which exhibited good thermal and storage stability with excellent reusability.Download high-res image (74KB)Download full-size image