title: Immobilization of organophosphate hydrolase on an amyloid fibril nanoscaffold: towards bioremediation and chemical detoxification.
abstract: Organophosphate hydrolase has potential as a bioremediation and chemical detoxification enzyme, but the problems of reusability and stability need to be addressed to use this enzyme on an industrial scale. Immobilizing the enzyme to a nanoscaffold may help to solve these problems. Amyloid fibrils generated from insulin and crystallin provided a novel nanoscaffold for the immobilization of organophosphate hydrolase, using glutaraldehyde as the crosslinking reagent. Electrophoretic, centrifugation, and temperature stability experiments, together with transmission electron microscopy were undertaken to verify that crosslinking had successfully occurred. The resulting fibrils remained active towards the substrate paraoxon and when immobilized to the insulin amyloid fibrils, the enzyme exhibited a significant (∼ 300%) increase in the relative temperature stability at 40, 45, and 50°C (as measured by comparing the initial enzyme activity to the activity remaining after heating), compared to free enzyme. This confirms that amyloid fibrils could provide a new type of nanoscaffold for enzyme immobilization.
authors.affiliation: Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, New Zealand. jkr31@uclive.ac.nz
authors.forename: Jared K
authors.initials: JK
authors.lastname: Raynes
authors.forename: F Grant
authors.initials: FG
authors.lastname: Pearce
authors.forename: Susie J
authors.initials: SJ
authors.lastname: Meade
authors.forename: Juliet A
authors.initials: JA
authors.lastname: Gerrard
mesh_terms: D000682:Amyloid / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002800:Cholinesterase Inhibitors / Q000378:metabolism; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000378:metabolism*; D006358:Hot Temperature; D007220:Industrial Waste / Q000517:prevention & control; D007306:Insecticides / Q000378:metabolism; D036103:Nanotechnology; D010261:Paraoxon / Q000378:metabolism; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism*
chemical_list: D000682:Amyloid; D002800:Cholinesterase Inhibitors; D004800:Enzymes, Immobilized; D007220:Industrial Waste; D007306:Insecticides; C045290:phosphorylphosphatase; D010744:Phosphoric Monoester Hydrolases; D010261:Paraoxon