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United States Department of Agriculture

Agricultural Research Service

Title: Purification of Desoxyhemigossypol O-Methyltransferase from Cotton Stems to Homogeneity by Affinity Chromatography

item Liu, Jinggao
item Benedict, Chauncey - TEXAS A&M UNIVERSITY
item Stipanovic, Robert
item Bell, Alois

Submitted to: American Chemical Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: January 4, 1998
Publication Date: N/A

Technical Abstract: Terpenoid aldehydes and naphthofuran precursors are synthesized in diseased cotton tissues as part of an active defense mechanism. The terpenoid aldehyde hemigossypol (HG) is derived by oxidation of the terpenoid naphthofuran desoxyhemigossypol (dHG). The enzyme dHG O-methyltransferase (dHG OMT) catalyses the transfer of a methyl group from S-adenosyl-L-methionine (SAM) to dHG to form desoxyhemigossypol-6-methyl ether (dMHG). dMHG can undergo the same oxidation as dHG to yield the methylated derivative of HG (i.e., hemigossypol-6-methyl ether). The methylated terpenoids are only about one-half as toxic as the unmethylated counterparts to microbial pathogens. Use of antisense technology may prevent the conversion of dHG to dMHG by blocking the synthesis of dHG OMT, and thereby increase resistance of the cotton plant to pathogens. In order to facilitate cloning of the dHG OMT gene, we are purifying the dHG OMT enzyme for sequence information. The purification of dHG OMT to homogeneity and the characterization of the enzyme will be presented.

Last Modified: 5/5/2015
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