Flavonoids as Substrates of Bacillus halodurans O-Methyltransferase

Bulletin of the Korean chemical society

Yong-Sic Hwang¹  Ki-Woong Jeong¹  Ju-Un Lee¹  Dong-Il Kang¹  Yangmee Kim¹  Jee-Young Lee¹ 

关键词: Methyltransferase;    Flavonoids;    Binding assay;    Docking;    Divalent metal;   

DOI  :  

学科分类：化学（综合）

来源: Korean Chemical Society

【 摘 要 】

Bacillus halodurans O-methyltransferase (BhOMT) is an S-adenosylmethionine dependent methyltransferase. In our previous study, three dimensional structure of the BhOMT has been determined by comparative homology modeling and automated docking study showed that two hydroxyl groups at 3`- and 4`-position in Bring and structural rigidity of C-ring resulting from the double bond characters between C2 and C3 of flavonoid, were key factors for interaction with BhOMT. In the present study, BhOMT was cloned and expressed. Binding assay was performed on purified BhOMT using fluorescence experiments and binding affinity of luteolin, quercetin, fisetin, and myricetin were measured in the range of 107. Fluorescence quenching experiments indicated that divalent cation plays a critical role on the metal-mediated electrostatic interactions between flavonoid and substrate binding site of BhOMT. Fluorescence study confirmed successfully the data obtained from the docking study and these results imply that hydroxyl group at 7-position of luteolin, quercetin, fisetin, and myricetin forms a stable hydrogen bonding with K211 and carboxyl oxygen of C-ring forms a stable hydrogen bonding with R170. Hydroxyl group at 3`-and 4`-position in the B-ring also has strong Ca2+ mediated electrostatic interactions with BhOMT.

【 授权许可】

Unknown