Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.10.3.2 (laccase)
 4,656 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Continuous gradient elution chromatography (CGEC) was employed to purify and separate enzymes and polysaccharides from the sap of Rhus vernicifera Chinese lacquer tree. There are three different molecules with laccase enzyme activity. Two are enzymes of each other (L1, and L2), whereas the third (RL) is an entirely separate entity. Two polysaccharides (GP1 and GP2) were also found. The Rhus laccase (RL), and isoenzymes L1 and L2, have peak molecular masses of 109,100, 120,000, 103,000 respectively; each has four copper atoms per molecule, and the pI values were 8.2, 8.6, and 9.1, respectively. The structure of the laccases was studied by Fourier-transform infrared (FT-IR) and Matrix-assisted laser desorption/ionization time-of flight (MALDI-TOF) mass spectrometry. The typical amide I (1646cm(-1)) and amide II (1545cm(-1)) bands were observed. The results from MALDI-TOF were similar to those from CGEC, but the molecular mass from the MALDI-TOF was significantly different from that obtained from sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE).
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PMID:Purification and characterization of hydrosoluble components from the sap of Chinese lacquer tree Rhus vernicifera. 1658 Jul 25

The purified polysaccharides, glycoproteins, and isoenzymes of Rhus laccase, and crude enzymes, from Chinese lacquer (Rhus vernicifera sap) were used to determine their influence on the enzymic activity of Rhus laccase on several substrates (4-phenylenediamine, isoeugenol and coniferyl alcohol). No product identity changes were observed when these components were added singularly or in combination to the enzymic reactions (only relative product yields varied significantly), however, the polysaccharides (GP1 and GP2) and glycoprotein (stellacyanin, St) exhibited negative effects, and the two isoenzymes (L1 and L2) exhibited positive synergistic effects, on the activity of Rhus laccase. With respect to the activity of the crude enzymes, the negative effects of GP1, GP2 and St were greater than the positive effects of L1 and L2, compared with free Rhus laccase on its own (using 4-phenylenediamine as substrate), the estimated inhibitory effect (of GP1, GP2 and St) being by at least a factor of 50 (even with the positive effect of L1 and L2). This contributes to understanding of lacquer storage stability and drying rates. Immobilisation of crude enzymes using a variety of techniques (using natural and modified polysaccharides, and an inorganic support) where evaluated using isoeugenol as substrate. Agar embedding and zirconium chloride chelation methods resulted in the highest substrate conversion levels. The yields and products of isoeugenol catalysis using Vietnamese crude enzymes/purified Rhus laccase and commercial Denilite laccase were also compared and contrasted with their Chinese lacquer sap equivalents.
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PMID:Effects of lacquer polysaccharides, glycoproteins and isoenzymes on the activity of free and immobilised laccase from Rhus vernicifera. 2036 47