Decarboxylation
of Fatty Acids to Terminal Alkenes
by Cytochrome P450 Compound I
Job L. Grant
Chun H. Hsieh
Thomas M. Makris
10.1021/jacs.5b01965.s001
https://acs.figshare.com/articles/journal_contribution/Decarboxylation_of_Fatty_Acids_to_Terminal_Alkenes_by_Cytochrome_P450_Compound_I/2174251
OleT<sub>JE</sub>, a cytochrome P450, catalyzes the conversion
of fatty acids to terminal alkenes using hydrogen peroxide as a cosubstrate.
Analytical studies with an eicosanoic acid substrate show that the
enzyme predominantly generates nonadecene and that carbon dioxide
is the one carbon coproduct of the reaction. The addition of hydrogen
peroxide to a deuterated substrate–enzyme (E–S) complex
results in the transient formation of an iron(IV) oxo π cation
radical (Compound I) intermediate which is spectroscopically indistinguishable
from those that perform oxygen insertion chemistries. A kinetic isotope
effect for Compound I decay suggests that it abstracts a substrate
hydrogen atom to initiate fatty acid decarboxylation. Together, these
results indicate that the initial mechanism for alkene formation,
which does not result from oxygen rebound, is similar to that widely
suggested for P450 monooxygenation reactions.
2015-04-22 00:00:00
hydrogen peroxide
P 450 monooxygenation reactions
oxygen insertion chemistries
alkene
substrate hydrogen atom
Compound
formation
eicosanoic acid substrate show
Cytochrome P 450