title: Phenolic substrates for fluorometric detection of laccase activity.
abstract: A fluorometric procedure has been developed for detection and estimation of laccase activity in fungal broth cultures. Laccase solution was pretreated with catalase for 1 h at 37 degrees C and pH 5. Homovanillic acid was then added and the reaction mixture incubated for a further hour at 37 degrees C. The fluorescence was then developed by addition of 0.1 M glycine buffer at pH 10. Laccase preparations from Pyricularia oryzae, Coriolus hirsutus and Pycnoporus cinnabarinus catalysed formation of a fluorescent product of HVA but the optimum pH values of enzyme activities varied. The culture fluids of several other fungi also catalysed development of fluorescence in solutions containing HVA. p-Hydroxyphenylacetic acid was a poor substrate for all laccases in vivo except that produced by Perennipora tephropora.
authors.affiliation: Centre for Applied Colloid and BioColloid Science, School of Chemical Sciences, Swinburne University of Technology, Hawthorn, Vic., Australia.
authors.forename: G
authors.initials: G
authors.lastname: Lonergan
authors.forename: E
authors.initials: E
authors.lastname: Mew
authors.forename: K
authors.initials: K
authors.lastname: Schliephake
authors.forename: W L
authors.initials: WL
authors.lastname: Baker
mesh_terms: D052160:Benzothiazoles; D005285:Fermentation; D005658:Fungi / Q000201:enzymology*; D006719:Homovanillic Acid / Q000378:metabolism; D006735:Horseradish Peroxidase / Q000378:metabolism; D006861:Hydrogen Peroxide; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents / Q000378:metabolism; D042845:Laccase; D010088:Oxidoreductases / Q000378:metabolism*; D010648:Phenylacetates / Q000378:metabolism*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013451:Sulfonic Acids
chemical_list: D052160:Benzothiazoles; D007202:Indicators and Reagents; D010648:Phenylacetates; D013451:Sulfonic Acids; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; C008070:4-hydroxyphenylacetic acid; D006861:Hydrogen Peroxide; D010088:Oxidoreductases; D042845:Laccase; D006735:Horseradish Peroxidase; D006719:Homovanillic Acid