title: Improving the activity and stability of actinidin by immobilization on gold nanorods.
abstract: Immobilization of actinidin was carried out by ionic exchange and hydrophobic interactions on gold nanorods synthesized via sequential seed-mediated growth method. The optimum temperature of actinidin increased from 40 to 60 °C and its optimum pH was shifted from 7 to 8.5 upon immobilization. The kinetic parameters, K(m) and k(cat), were found to be 12.5 μM and 29.2 s(-1) for free and 15.92 μM and 20.74 s(-1) for immobilized actinidin, respectively. Immobilization process caused significant enhancement of shelf-life stability and resistance against the inhibitory effects of various bivalent metal ions with respect to actinidin. Enzymes show higher functionality than the free form when incubated for long time (1h) at 80 °C and at extreme pH values (3 and 12). The reasons of this enhanced stability of immobilized actinidin are discussed.
authors.affiliation: Department of Biochemistry, Faculty of Sciences, University of Hormozgan, Bandar Abbas, Iran. Electronic address: a.homaei@hormozgan.ac.ir.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Homaei
authors.affiliation: Department of Horticulture, Faculty of Agriculture, University of Hormozgan, Bandar Abbas, Iran.
authors.forename: Rasoul
authors.initials: R
authors.lastname: Etemadipour
mesh_terms: D003546:Cysteine Endopeptidases / Q000378:metabolism*; D004795:Enzyme Stability / Q000187:drug effects; D004800:Enzymes, Immobilized / Q000378:metabolism*; D006046:Gold / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007477:Ions; D007700:Kinetics; D008670:Metals / Q000494:pharmacology; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature
chemical_list: D004800:Enzymes, Immobilized; D007477:Ions; D008670:Metals; D006046:Gold; D003546:Cysteine Endopeptidases; C018745:actinidain
keywords: Actinidin; Extreme pHs.; Gold nanorods; Immobilization; Thermal stability