PURIFICATION AND PROPERTIES OF CAFFEIC ACID O-METHYLTRANSFERASE FROM ALFALFA ROOT NODULES

Article abstract of DOI:10.1016/0031-9422(81)85215-6

An O-methyltransferase which catalyses the methylation of caffeic acid to ferulic acid using S-adenosyl-L-methionine as methyl donor has been isolated and purified ca. 70-fold from root nodules of alfalfa.The enzyme also catalysed the methylation of 5-fydroxyferulic acid.Chromatography on 1,6-diaminohexane agarose (AH-Sepharose4B) linked with S-adenosyl-L-homocysteine (SAH) gave 35 percent recovery of enzyme activity.The K_m values for caffeic acid ans S-adenosyl-L-methionine were 58 and 4.1 μM, respectively.S-Adenosyl-L-homocysteins was a potent competitive inhibitor of S-adenosyl-L-methionine with a K_i of 0.44 μM.The MW of the enzyme was ca. 103 000 determined by gel filtration chromatography.