title: Horseradish peroxidase immobilized through its carboxylic groups onto a polyacrylonitrile membrane: comparison of enzyme performances with inorganic beaded supports.
abstract: A hydrophilic polyacrylonitrile (PAN) flat sheet membrane was aminated (8.5 micromol of NH2/mg of dry support) for covalent binding of horseradish peroxidase (HRP), mediated by the soluble carbodiimide l-ethyl-3-(3- dimethylaminopropyl)carbodiimide (EDC). Silica microbeads derivatized by silanization, to yield an aminated support, and commercial aminated glass microbeads were also coupled to HRP with EDC or activated with glutaraldehyde. The immobilized enzyme activities were determined in a batch enzyme reactor with an external loop, the highest specific immobilized HRP activity being obtained on the glass support (55.8 U/mg of protein). Continuous operational stability studies showed that hydrophilic PAN membrane led to the highest retention of HRP activity after an overall period of 35 h, with a normalized productivity of 59.5 micromol of H2O2 reduced/(h x Uimmob HRP).
authors.affiliation: Centro de Engenharia Biológica e Química, Instituto Superior Técnico, 1049-001 Lisboa, Portugal.
authors.forename: P R S
authors.initials: PR
authors.lastname: Leirião
authors.forename: L J P
authors.initials: LJ
authors.lastname: Fonseca
authors.forename: M A
authors.initials: MA
authors.lastname: Taipa
authors.forename: J M S
authors.initials: JM
authors.lastname: Cabral
authors.forename: M
authors.initials: M
authors.lastname: Mateus
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D001709:Biotechnology; D002234:Carbodiimides / Q000737:chemistry; D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D005022:Ethyldimethylaminopropyl Carbodiimide / Q000031:analogs & derivatives* / Q000737:chemistry; D005898:Glass / Q000737:chemistry; D005976:Glutaral / Q000737:chemistry; D006735:Horseradish Peroxidase / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D007700:Kinetics; D010100:Oxygen / Q000737:chemistry; D013997:Time Factors
chemical_list: D000180:Acrylic Resins; D002234:Carbodiimides; C010504:polyacrylonitrile; C041829:1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide methiodide; D002244:Carbon; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase; D005022:Ethyldimethylaminopropyl Carbodiimide; D010100:Oxygen; D005976:Glutaral