University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Email: schalk@unf.edu
Website: @unf

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Enzyme, laccase

@ ChemSpider@ NIST@ PubChem

Citations 3

"Micelle Enhanced Spectrofluorimetric Assay For Laccase Activity By A Flow Injection Stopped-flow Technique"
Anal. Chim. Acta 1995 Volume 318, Issue 1 Pages 63-69
Houping Huang*, Ruxiu Cai, Yumin Du, Zhixin Lin and Yune Zeng

Abstract: An automated flow injection stopped-flow kinetic spectrofluorimetric method for determination of laccase activity is proposed. It is based on the oxidation of o-phenylenediamine (1,2-diaminobenzene) catalyzed by laccase during the stopped-flow period, yielding 2,3-diaminophenazine, which is determined by a micelle enhanced spectrofluorimetric method in a non-ionic surfactant medium. The substrate solution with Brij-35 and the buffer with sample are pumped into the flow manifold at the same flow rate and merged in the flow cell, then stopped for measuring the fluorescence intensity (lambda-ex = 425 nm, lambda-em = 530 nm) which increases with time, at a constant temperature of 46°C. The linear range of the method is 0.1-118 U L-1 with a detection limit of 0.07 U l-1, using a 5 min stopped-flow reaction time. The proposed method has been applied to the assay for laccase activity of real samples at 10 samples per h.
Fluorescence Heated reaction Stopped-flow Micelle Surfactant

"Laccase Electrode For Organic-phase Enzymic Assays"
Anal. Lett. 1993 Volume 26, Issue 2 Pages 197-207
Wang, J.;Lin, Y.H.;Eremenko, A.V.;Ghindilis, A.L.;Kurochkin, I.N.

Abstract: A vitreous carbon electrode was coated with a 20 µL drop of a 1.4% solution of poly(ester-sulfonic acid) polymer (I) containing 60 µg of laccase (II) for batch experiments or with a 10 µL drop of a 0.7% solution of I containing 30 µg of II for flow injection work. Amperometric responses of the biosensor to successive 0.1 mM increments of methylcatechol, catechol and hydroquinone (III) in various organic solvents, each containing 5% water and 0.1 M tetraethylammonium p-toluene sulfonate, were made at 0.35 V vs. Ag - AgCl, with an auxiliary electrode of Pt wire and stirring at 300 rpm. The detection limit for III in butan-1-ol was 0.6 µM and calibration graphs were rectilinear from 2 to 20 µM. For flow injection, 60 samples h-1 were processed with a coefficient of variation of 1.3%.
Electrode Electrode Sensor Organic phase detection

"The Automatic Kinetic Spectrophotometric Assay For Laccase Activity Using O-phenylenediamine"
Lab. Rob. Autom. 1996 Volume 8, Issue 4 Pages 231-235
Houping Huang*, Ruxiu Cai, Yumin Du, Yun'e Zeng

Abstract: An automatic flow-injection stopped-flow kinetic spectrophotometric method for determination of laccase activity is proposed. It is based on the oxidation of o-phenylenediamine (1,2-diaminobenzene) catalyzed by laccase during the stopped-flow period, yielding 2,3-diaminophenazine, which is determined spectrophotometrically. The substrate solution (o-phenylenediamine) and Na2HPO4-HAc (pH 6.20) buffer with sample (laccase) are pumped into the flow manifold via two separated channels at the same flow velocity and merged in the flow-through cell, then stopped for measuring variation of absorbance at 420 nm with time at a constant temperature of 55°C. The linear range of the method is over 0-2 U, and the detection limitation is 0.012 U. The proposed method has been applied to the analysis of laccase activity of real samples at 30 samples per hour.
Spectrophotometry Automation Kinetic