title: Self-assembled organic-inorganic hybrid glucoamylase nanoflowers with enhanced activity and stability.
abstract: An organic-inorganic hybrid glucoamylase nanoflower was prepared in single pot by simple, facile and highly efficient method. The stepwise formation of enzyme-embedded hybrid nanoflowers and influence of experimental parameters viz. pH of solution mixture, enzyme and copper ion concentration on the activity of prepared hybrid nanoflowers were systematically investigated. The self-assembled hybrid glucoamylase nanoflowers were synthesized by mixing aqueous solution of copper sulphate (200mM) with PBS (pH 7.5, 5mM) containing glucoamylase (1mg/mL) in 24h at room temperature. These prepared nanoflowers were further characterized by FT-IR, SEM and XRD. The hybrid nanoflowers exhibited 204% enhanced activity recovery and two folds improvement in thermal stability in terms of half-life (in the range of 50-70°C) with respect to the free form. The hybrid glucoamylase nanoflowers retained 70% residual activity after eight successive cycles indicating their excellent durability. Additionally, the nanoflowers retained up to 91% residual activity upto 25 days of storage. Moreover, the conformational changes occurred in glucoamylase structure after preparing hybrid nanoflowers were evaluated by FT-IR spectroscopy data tools.
authors.affiliation: Department of Chemical Engineering, Institute of Chemical Technology, Matunga (E) Mumbai 400019, India.
authors.forename: Shamraja S
authors.initials: SS
authors.lastname: Nadar
authors.affiliation: Department of Chemical Engineering, Institute of Chemical Technology, Matunga (E) Mumbai 400019, India.
authors.forename: Sarita D
authors.initials: SD
authors.lastname: Gawas
authors.affiliation: Department of Chemical Engineering, Institute of Chemical Technology, Matunga (E) Mumbai 400019, India. Electronic address: vk.rathod@ictmumbai.edu.in.
authors.forename: Virendra K
authors.initials: VK
authors.lastname: Rathod
mesh_terms: D004789:Enzyme Activation; D004795:Enzyme Stability; D005087:Glucan 1,4-alpha-Glucosidase / Q000737:chemistry* / Q000648:ultrastructure; D007287:Inorganic Chemicals / Q000737:chemistry*; D007700:Kinetics; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D009930:Organic Chemicals / Q000737:chemistry*; D017433:Protein Structure, Secondary; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature
chemical_list: D007287:Inorganic Chemicals; D009930:Organic Chemicals; D005087:Glucan 1,4-alpha-Glucosidase
keywords: Enhanced activity; Glucoamylase; Immobilization; Nanoflowers; Organic–inorganic hybrid