title: Investigation of activity and stability of papain by adsorption on multi-wall carbon nanotubes.
abstract: Papain was non-covalently immobilized on multi-walled carbon nanotubes (MWCNTs). Its stabilities and catalytic activity for casein degradation were comprehensively investigated. Compared to free papain, the nano-enzyme exhibited significantly improved thermal, pH and recycling stability. Comparisons of the kinetic parameters between free papain and the heterogeneous enzyme revealed that the Kmvalue of the immobilized papain experienced a slight increase, which suggested that the MWCNTs did not significantly hinder papain's access to substrate or release of product. This feature is beneficial to the industrial applications because of its potential to be easily separated from the end product at the end of the reaction, reuse for multiple times and allow the development of multiple enzyme reaction system.
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 Chemistry, Faculty of Sciences, University of Hormozgan, Bandar Abbas, Iran.
authors.forename: Fayezeh
authors.initials: F
authors.lastname: Samari
mesh_terms: D000327:Adsorption; D055162:Biocatalysis; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010206:Papain / Q000737:chemistry* / Q000378:metabolism*; D012995:Solubility; D013696:Temperature
chemical_list: D004800:Enzymes, Immobilized; D037742:Nanotubes, Carbon; D010206:Papain
keywords: Immobilization; Kinetic parameters; Multi-walled carbon nanotubes; Papain