syringaldazine has been researched along with sinapinic-acid* in 2 studies
2 other study(ies) available for syringaldazine and sinapinic-acid
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Prediction model based on decision tree analysis for laccase mediators.
A Structure Activity Relationship (SAR) study for laccase mediator systems was performed in order to correctly classify different natural phenolic mediators. Decision tree (DT) classification models with a set of five quantum-chemical calculated molecular descriptors were used. These descriptors included redox potential (ɛ°), ionization energy (E(i)), pK(a), enthalpy of formation of radical (Δ(f)H), and OH bond dissociation energy (D(O-H)). The rationale for selecting these descriptors is derived from the laccase-mediator mechanism. To validate the DT predictions, the kinetic constants of different compounds as laccase substrates, their ability for pesticide transformation as laccase-mediators, and radical stability were experimentally determined using Coriolopsis gallica laccase and the pesticide dichlorophen. The prediction capability of the DT model based on three proposed descriptors showed a complete agreement with the obtained experimental results. Topics: Acetophenones; Benzaldehydes; Biocatalysis; Catechols; Coumaric Acids; Decision Trees; Dichlorophen; Fungal Proteins; Hydrazones; Laccase; Models, Chemical; Models, Molecular; Molecular Structure; Nitrophenols; Oxidation-Reduction; Phenols; Polyporales; Protein Conformation; Quantitative Structure-Activity Relationship; Vanillic Acid | 2013 |
Purification and characterization of the constitutive form of laccase from the basidiomycete Coriolus hirsutus and effect of inducers on laccase synthesis.
An isolate of Coriolus hirsutus constitutively expresses substantial amounts of extracellular laccase on a defined growth medium. The most efficient inducer of extracellular laccase synthesis was syringaldazine, which increased the enzyme yield by 1000% at a concentration of 0.11 microM. The constitutive form of the enzyme was purified 312-fold. Laccase from C. hirsutus, with an estimated molecular mass of 55 kDa and pI of 4.0, is a monomeric glycoprotein containing 12% carbohydrate consisting of mannose and N-acetylglucosamine. The laccase was found to contain 3.9-4.1 copper atoms per molecule. The absorption spectrum shows a maximum at 610 nm and a shoulder at 330 nm, which is typical of laccase possessing type 1 and type 3 copper atoms. The parameters of the first type of copper were determined by EPR as g perpendicular=2.046 and g parallel=2.200, A parallel=8.103 x 10(-3) cm-1. Laccase was found to be a pH-stable and thermostable enzyme. With organic substrates it exhibits a pH optimum of 4.5, but with the inorganic substrate K4[Fe(CN)6] this decreased to 3.5. The highest efficiency of catalysis was observed with sinapinic acid as the substrate. The kinetic constants kcat and Km of this reaction were 578 s-1 and 24 microM respectively. It was established that the kinetics of the assayed reaction shows a Ping Pong mechanism. Topics: Amino Acids; Basidiomycota; Coumaric Acids; Electron Spin Resonance Spectroscopy; Enzyme Induction; Fungal Proteins; Glycoproteins; Hydrazones; Hydrogen-Ion Concentration; Isoenzymes; Kinetics; Laccase; Metalloproteins; Oxidoreductases; Spectrophotometry; Substrate Specificity | 1998 |