title: Competitive adsorptions of nitrile hydratase and amidase on polyacrylonitrile and its effect on surface modification.
abstract: In this study, enzymatic surface modification of polyacrylonitrile was studied using nitrile metabolizing enzyme of Amycolatopsis sp. IITR 215. During enzymatic treatment of polyacrylonitrile at pH of 5.8 and 7, it was observed that the conversion of cyano group to carboxylic acid at pH 5.8 was three times higher than at pH 7. This difference in enzymatic treatment efficiency was explained by studying the differences in adsorption profiles of nitrile hydratase and amidase on polyacrylonitrile at pH of 5.8 and 7. Adsorption profiles were determined by monitoring the unbound activities of these two enzymes in the supernatant. From the specific activity profiles of bound nitrile hydratase and amidase it was concluded that more specific binding of nitrile hydratase was observed at pH 5.8 as compared to pH 7. In case of amidase, optimum adsorption was obtained at pH 5.8 within 5h whereas in case of pH 7 it was obtained within 20 h. Thus at pH 7, sequential adsorption of nitrile hydratase and amidase was observed and this adsorption profile was similar to the Vroman effect reported during plasma protein adsorption at solid-liquid interface. Ideally, specific nitrile hydratase adsorption followed by sequential adsorption of amidase may enhance higher conversion of cyano group to carboxylic acid.
authors.affiliation: Department of Biotechnology, Indian Institute of Technology, Roorkee 247 667, India.
authors.forename: Vikash
authors.initials: V
authors.lastname: Babu
authors.forename: Bijan
authors.initials: B
authors.lastname: Choudhury
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000327:Adsorption; D000581:Amidohydrolases / Q000737:chemistry*; D002474:Cell-Free System; D006836:Hydro-Lyases / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D013499:Surface Properties
chemical_list: D000180:Acrylic Resins; C010504:polyacrylonitrile; D000581:Amidohydrolases; C019665:amidase; D006836:Hydro-Lyases; C048831:nitrile hydratase