title: Specificity of glucose oxidase from Penicillium funiculosum 46.1 towards some redox mediators.
abstract: Glucose oxidase (GOx) from Penicillium funiculosum 46.1 was purified using step-by-step ultrafiltration and it was characterized by spectrophotometric and spectrofluorometric methods. It was shown that spectra of GOx produced by P. funiculosum are typical for flavoproteins. Absorption spectrum has distinct peaks at 380 and 457 nm, excitation spectrum at 373 and 447 nm, and emission spectrum at 530 and 562 nm. The pH correlation of enzyme activity and catalytic characteristics in various buffer systems (phosphate (pH 5.0-9.0), citrate (pH 3.0-5.0), citrate-phosphate (pH 3.0-9.0), and universal (pH 3.0-9.0)) were registered. It was determined that the GOx is the most efficiently interacting with substrate (glucose) in phosphate buffer at pH 7.0 with k cat/K m = 21,825 M(-1) s(-1). Interaction of several different redox mediators (9,10-phenantroline-5,6-dione, 9,10-phenanthrenequinone, N-methylphenazonium methyl sulfate, ferrocene, ferrocenecarboxylic acid, α-methylferrocenemethanol, ferrocenecarboxaldehyde) with GOx from P. funiculosum was investigated by evaluation of the difference in fluorescence emission intensity of FAD(oxidized) and FADH2(reduced) forms. It was found that 9,10-phenantroline-5,6-dione and 9,10-phenanthrenequinone are the best redox mediators for this type of GOx.
authors.affiliation: Institute of Microbiology of Belarus National Academy of Sciences, Kuprevich str., 2, Minsk, 220141, Belarus.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Semashko
authors.forename: Raisa
authors.initials: R
authors.lastname: Mikhailova
authors.forename: Almira
authors.initials: A
authors.lastname: Ramanaviciene
authors.forename: Arunas
authors.initials: A
authors.lastname: Ramanavicius
mesh_terms: D055162:Biocatalysis; D005182:Flavin-Adenine Dinucleotide / Q000031:analogs & derivatives / Q000378:metabolism; D005949:Glucose Oxidase / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D010407:Penicillium / Q000201:enzymology*; D013379:Substrate Specificity
chemical_list: D005182:Flavin-Adenine Dinucleotide; C058805:1,5-dihydro-FAD; D005949:Glucose Oxidase