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Partial purification, kinetic analysis, and amino acid sequence information of a flavonol 3-O-methyltransferase from Serratula tinctoria.

Author(s): Huang TS, Anzellotti D, Dedaldechamp F, Ibrahim RK

Plant Physiol. 2004 Apr;134(4):1366-76 Authors: Huang TS, Anzellotti D, Dedaldechamp F, Ibrahim RK

Article GUID: 15084728
Effects of surfactants on rhizodegradation of oil in a contaminated soil.

Author(s): Memarian R, Ramamurthy AS

J Environ Sci Health A Tox Hazard Subst Environ Eng. 2012;47(10):1486-90 Authors: Memarian R, Ramamurthy AS

Article GUID: 22571537
Enzymatic assay for GHB determination in forensic matrices.

Author(s): Grenier V, Huppé G, Lamarche M, Mireault P

J Anal Toxicol. 2012 Sep;36(7):523-8 Authors: Grenier V, Huppé G, Lamarche M, Mireault P

Article GUID: 22722059
Odorous gaseous emissions as influence by process condition for the forced aeration composting of pig slaughterhouse sludge.

Author(s): Blazy V, de Guardia A, Benoist JC, Daumoin M, Lemasle M, Wolbert D, Barrington S

Waste Manag. 2014 Jul;34(7):1125-38 Authors: Blazy V, de Guardia A, Benoist JC, Daumoin M, Lemasle M, Wolbert D, Barrington S

Article GUID: 24768513
Development of a particle-trap preconcentration-soft ionization mass spectrometric technique for the quantification of mercury halides in air

Author(s): Deeds DA; Ghoshdastidar A; Raofie F; Guérette ÉA; Tessier A; Ariya PA;

Measurement of oxidized mercury, Hg(II), in the atmosphere poses a significant analytical challenge as Hg(II) is present at ultra-trace concentrations (picograms per cubic meter air). Current technologies are sufficiently sensitive to measure the total Hg p...

Article GUID: 25837315
Lithocholic bile acid accumulated in yeast mitochondria orchestrates a development of an anti-aging cellular pattern by causing age-related changes in cellular proteome.

Author(s): Beach A, Richard VR, Bourque S, Boukh-Viner T, Kyryakov P, Gomez-Perez A, Arlia-Ciommo A, Feldman R, Leonov A, Piano A, Svistkova V, Titorenko VI

Cell Cycle. 2015;14(11):1643-56 Authors: Beach A, Richard VR, Bourque S, Boukh-Viner T, Kyryakov P, Gomez-Perez A, Arlia-Ciommo A, Feldman R, Leonov A, Piano A, Svistkova V, Titorenko VI

Article GUID: 25839782
Electrochemical efficacy of a carboxylated multiwalled carbon nanotube filter for the removal of ibuprofen from aqueous solutions under acidic conditions.

Author(s): Bakr AR, Rahaman MS

Chemosphere. 2016 Jun;153:508-20 Authors: Bakr AR, Rahaman MS

Article GUID: 27035389
On-chip integration of droplet microfluidics and nanostructure-initiator mass spectrometry for enzyme screening

Author(s): Joshua Heinemann

Biological assays often require expensive reagents and tedious manipulations. These shortcomings can be overcome using digitally operated microfluidic devices that require reduced sample volumes to automate assays. One particular challenge is integrating bi...

Article GUID: 27957569
Varying the rate of intravenous cocaine infusion influences the temporal dynamics of both drug and dopamine concentrations in the striatum

Author(s): Minogianis EA; Shams WM; Mabrouk OS; Wong JT; Brake WG; Kennedy RT; du Souich P; Samaha AN;...

The faster drugs of abuse reach the brain, the greater is the risk of addiction. Even small differences in the rate of drug delivery can influence outcome. Infusing cocaine intravenously over 5 vs....

Article GUID: 29757478
Title:Partial purification, kinetic analysis, and amino acid sequence information of a flavonol 3-O-methyltransferase from Serratula tinctoria.
Authors:Huang TS,  Anzellotti D,  Dedaldechamp F,  Ibrahim RK
Link:https://www.ncbi.nlm.nih.gov/pubmed/15084728?dopt=Abstract
DOI:10.1104/pp.103.036442
Category:Plant Physiol
PMID:15084728
Dept Affiliation: MASSSPEC
1 Plant Biochemistry Laboratory and Centre for Structural and Functional Genomics, Concordia University, Montreal, Quebec, Canada H4B 1R6.

Description:

Partial purification, kinetic analysis, and amino acid sequence information of a flavonol 3-O-methyltransferase from Serratula tinctoria.

Plant Physiol. 2004 Apr;134(4):1366-76

Authors: Huang TS, Anzellotti D, Dedaldechamp F, Ibrahim RK

Abstract

Serratula tinctoria (Asteraceae) accumulates mainly 3,3'-dimethylquercetin and small amounts of 3-methylquercetin as an intermediate. The fact that 3-methylquercetin rarely accumulates in plants in significant amounts, and given its important role as an antiviral and antiinflammatory agent that accumulates in response to stress conditions, prompted us to purify and characterize the enzyme involved in its methylation. The flavonol 3-O-methyltransferase (3-OMT) was partially purified by ammonium sulfate precipitation and successive chromatography on Superose-12, Mono-Q, and adenosine-agarose affinity columns, resulting in a 194-fold increase of its specific activity. The enzyme protein exhibited an expressed specificity for the methylation of position 3 of the flavonol, quercetin, although it also utilized kaempferol, myricetin, and some monomethyl flavonols as substrates. It exhibited a pH optimum of 7.6, a pI of 6.0, and an apparent molecular mass of 31 kD. Its K(m) values for quercetin as the substrate and S-adenosyl-l-Met (AdoMet) as the cosubstrate were 12 and 45 microm, respectively. The 3-OMT had no requirement for Mg(2+), but was severely inhibited by p-chloromercuribenzoate, suggesting the requirement for SH groups for catalytic activity. Quercetin methylation was competitively inhibited by S-adenosyl-l-homo-Cys with respect to the cosubstrate AdoMet, and followed a sequential bi-bi reaction mechanism, where AdoMet was the first to bind and S-adenosyl-l-homo-Cys was released last. In-gel trypsin digestion of the purified protein yielded several peptides, two of which exhibited strong amino acid sequence homology, upon protein identification, to a number of previously identified Group II plant OMTs. The availability of peptide sequences will allow the design of specific nucleotide probes for future cloning of the gene encoding this novel enzyme for its use in metabolic engineering.

PMID: 15084728 [PubMed - indexed for MEDLINE]