Results 151 to 160 of about 19,268 (196)

Selective sensing of catechol based on a fluorescent nanozyme with catechol oxidase activity

Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy, 2023
Nanozymes, an unusual category of nanomaterials possessing enzymatic properties, and have generated considerable interest regarding their application feasibilities on several important fronts. In the present work, an innovative sensing device for catechol was established ground on a fluorescent nanozyme (Cu-BDC-NH2) that exhibited catechol oxidase ...
Yongxin Li
exaly   +3 more sources

The catalytic cycle of catechol oxidase

Journal of Biological Inorganic Chemistry, 2004
Hybrid density functional theory with the B3LYP functional has been used to investigate the catalytic mechanism of catechol oxidase. Catechol oxidase belongs to a class of enzymes that has a copper dimer with histidine ligands at the active site. Another member of this class is tyrosinase, which has been studied by similar methods previously.
Per Siegbahn, Siegbahn Per E M
exaly   +3 more sources

Amperometric catechol biosensor based on polyaniline–polyphenol oxidase

Biosensors and Bioelectronics, 2010
A novel catechol biosensor was described based on the immobilization of polyphenol oxidase (PPO) into polyaniline (PANI), which was easily constructed by direct electropolymerization of aniline in a solution containing ionic liquid, 1-ethyl-3-methylimidazolium ethyl sulfate (EMIES).
Jinqing Kan
exaly   +3 more sources

Tyrosinase versus Catechol Oxidase: One Asparagine Makes the Difference

Angewandte Chemie - International Edition, 2016
AbstractTyrosinases mediate the ortho‐hydroxylation and two‐electron oxidation of monophenols to ortho‐quinones. Catechol oxidases only catalyze the oxidation of diphenols. Although it is of significant interest, the origin of the functional discrimination between tyrosinases and catechol oxidases has been unclear. Recently, it has been postulated that
Felix Tuczek
exaly   +3 more sources

Platinum Nanoparticles: Efficient and Stable Catechol Oxidase Mimetics

ACS Applied Materials & Interfaces, 2015
Although enzyme-like nanomaterials have been extensively investigated over the past decade, most research has focused on the peroxidase-like, catalase-like, or SOD-like activity of these nanomaterials. Identifying nanomaterials having oxidase-like activities has received less attention. In this study, we demonstrate that platinum nanoparticles (Pt NPs)
Zhihong Nie, Yu Chong, Jun-Jie Yin
exaly   +3 more sources

Evidence for conformational changes in grape catechol oxidase

Phytochemistry, 1972
Abstract A rapid, 4–10-fold, activation of grape catechol oxidase by a short exposure to acid pH or urea is demonstrated. Activation was either reversible or irreversible, depending on length and type of treatment. The change in activity of the enzyme is due primarily to an increase in V max , while the affinity for 4-methylcatechol decreases and ...
A M Mayer, E Harel
exaly   +2 more sources

Zero‐Order Catechol Oxidase Activity by a Mononuclear Manganese(III) Complex Showing High Turnover Comparable to Catechol Oxidase Enzyme

ChemCatChem, 2013
Enzymatic mimics are designed by using small molecules to impart insight into the mechanistic pathways of the enzymes and to generate catalysts that could be as efficient as the enzyme itself. Among the copper-based polyphenol oxidase enzymes, the copper(II)-containing enzyme catechol oxidase catalyses exclusively the oxidation of ortho-diphenols to ...
Suman Kr Dey, Arindam Mukherjee
exaly   +2 more sources

Oxidation of Catechol by Tea-Oxidase

Nature, 1950
DURING the enzymic oxidation of catechol, approximately two atoms of oxygen are taken up for each molecule of catechol, whereas only one atom is required for oxidation to the o-quinone stage. Wagreich and Nelson1 consider this extra uptake to be accounted for by the interaction of the o-benz-quinone with water to form 1 : 2 : 4-trihydroxy-benzene ...
E A H, ROBERTS, D J, WOOD
openaire   +2 more sources

Coniferyl alcohol oxidase ? a catechol oxidase?

Trees, 1995
The physico-chemical properties of coniferyl alcohol oxidase (CAO), a copper containing glycoprotein spatiotemporally associated with lignification in conifers, is reported here. By electron paramagnetic resonance spectroscopy, only type 3 copper was indicated in CAO. CAO oxidizes several laccase substrates; however, it is not a blue-copper protein and
PreethiV. Udagama-Randeniya, RodneyA. Savidge   +1 more
openaire   +1 more source

Tyrosinase and Catechol Oxidase

Nature, 1938
THE nature of tyrosinase has been under discussion for a very long time. Raper and his school1, Graubard and Nelson2, and Keilin and Mann3 believe it to be a distinct enzyme, different from catechol oxidase. Onslow and Robinson4, McCance5, and Richter6 believe it to be a catechol oxidase plus o-chinone plus dehydrogenase. Kubowitz7, whose work appeared
L. CALIFANO, D. KERTESZ
openaire   +1 more source