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The first cytochrome P450 in ferns
Author(s) -
Canals Daniel,
IrurreSantilari Josep,
Casas Josefina
Publication year - 2005
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/j.1742-4658.2005.04897.x
Subject(s) - cytochrome p450 , hydroxylation , callus , microsome , biochemistry , bioconversion , heme , substrate (aquarium) , biology , chemistry , enzyme , botany , fermentation , ecology
The fern Polypodium vulgare is a phytoecdysteroid (PE)‐producing plant. Cultures of P. vulgare prothalus produce PE, whereas prothalus‐derived callus cultures do not. However, this callus line can transform topically applied ecdysone (E) to 20‐hydroxyecdysone (20E), which is the last step in the biosynthetic pathway of the main plant PE. This hydroxylation is catalysed by a cytochrome P450 enzyme. E treatment of the callus line results in an increased amount of P450, showing a linear correspondence between the amount of P450 and in vivo E 20‐hydroxylation activity , estimated by measuring the bioconversion of E to 20E. This activity can be inhibited by molecules that bind to the P450‐heme group. E shows a P450‐substrate‐binding spectrum with microsomes that overexpress the P450 protein. Finally, a P450 protein was purified from E‐treated calli, this being the first P450 to be described in the pterydophyte group.