View : 24 Download: 0

Cytochrome P450-catalyzed brassinosteroid pathway activation through synthesis of castasterone and brassinolide in Phaseolus vulgaris

Title
Cytochrome P450-catalyzed brassinosteroid pathway activation through synthesis of castasterone and brassinolide in Phaseolus vulgaris
Authors
Kim T.-W.Chang S.C.Lee J.S.Hwang B.Takatsuto S.Yokota T.Kim S.-K.
Ewha Authors
이준승
SCOPUS Author ID
이준승scopusscopus
Issue Date
2004
Journal Title
Phytochemistry
ISSN
0031-9422JCR Link
Citation
vol. 65, no. 6, pp. 679 - 689
Indexed
SCI; SCIE; SCOPUS WOS scopus
Abstract
The last reaction in the biosynthesis of brassinolide has been examined enzymatically. A microsomal enzyme preparation from cultured cells of Phaseolus vulgaris catalyzed a conversion from castasterone to brassinolide, indicating that castasterone 6-oxidase (brassinolide synthase) is membrane associated. This enzyme preparation also catalyzed the conversions of 6-deoxocastasterone and typhasterol to castasterone which have been reported to be catalyzed by cytochrome P450s, CYP85A1 of tomato and CYP92A6 of pea, respectively. The activities of these enzymes require molecular oxygen as well as NADPH as a cofactor. The enzyme activities were strongly inhibited by carbon monoxide, an inhibitor of cytochrome P450, and this inhibition was recovered by blue light irradiation in the presence of oxygen. Commercial cytochrome P450 inhibitors including cytochrome c, SKF 525A, 1-aminobenzotriazole and ketoconazole also inhibited the enzyme activities. The present work presents unanimous enzymological evidence that cytochrome P450s are responsible for the synthesis of brassinolide from castasterone as well as of castasterone from typhasterol and 6-deoxocastasterone, which have been deemed activation steps of BRs. © 2004 Elsevier Ltd. All rights reserved.
DOI
10.1016/j.phytochem.2004.01.007
Appears in Collections:
자연과학대학 > 생명과학전공 > Journal papers
Files in This Item:
There are no files associated with this item.
Export
RIS (EndNote)
XLS (Excel)
XML


qrcode

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

BROWSE