Elucidation of the methyl transfer mechanism catalyzed by chalcone O-methyltransferase: A density functional study

✍ Scribed by Feng-Chao Cui; Xiao-Liang Pan; Wei Liu; Jing-Yao Liu

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 950 KB
• Volume: 32
• Category: Article
• ISSN: 0192-8651
• DOI: 10.1002/jcc.21890

✦ Synopsis

Abstract

The mechanism of the methyl transfer catalyzed by chalcone O‐methyltransferase has been computationally investigated by employing the hybrid functional B3LYP. Two models are constructed based on the two conformations of the substrate isoliquiritigenin in the X‐ray structure. Our calculations show that the overall reaction is divided into two elementary steps: the water‐assisted deprotonation of the substrate by His278 as a catalytic base, followed by the methyl transfer from S‐adenosyl‐L‐methionine (SAM) to the substrate. The calculated rate‐limiting barriers for the methyl‐transfer step indicate that the catalytic reactions are energetically feasible for both conformations adopted by the substrate. Copyright for JCC Journal: © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011