In this section
@article{van:2015:10.1016/j.fob.2015.10.007,
author = {van, Wilderen L and Silkstone, G and Mason, M and van, Thor J and Wilson, MT},
doi = {10.1016/j.fob.2015.10.007},
journal = {FEBS Open Bio},
pages = {885--892},
title = {Kinetic studies on the oxidation of semiquinone and hydroquinone forms of Arabidopsis cryptochrome by molecular oxygen},
url = {http://dx.doi.org/10.1016/j.fob.2015.10.007},
volume = {5},
year = {2015}
}
TY - JOUR
AB - Cryptochromes (crys) are flavoprotein photoreceptors present throughout the biological kingdom that play important roles in plant development and entrainment of the circadian clock in several organisms. Crys noncovalently bind flavin adenine dinucleotide (FAD) which undergoes photoreduction from the oxidised state to a radical form suggested to be active in signalling in vivo. Although the photoreduction reactions have been well characterised by a number of approaches, little is known of the oxidation reactions of crys and their mechanisms. In this work, a stoppedflow kinetics approach is used to investigate the mechanism of cry oxidation in the presence and absence of an external electron donor. This in vitro study extends earlier investigations of the oxidation of Arabidopsis cryptochrome1 by molecular oxygen and demonstrates that, under some conditions, a more complex model for oxidation of the flavin than was previously proposed is required to accommodate the spectral evidence (see P. Müller and M. Ahmad (2011) J. Biol. Chem. 286, 21033–21040 [1]). In the absence of an electron donor, photoreduction leads predominantly to the formation of the radical FADH. Dark recovery most likely forms flavin hydroperoxide (FADHOOH) requiring superoxide. In the presence of reductant (DTT), illumination yields the fully reduced flavin species (FADH−). Reaction of this with dioxygen leads to transient radical (FADH) and simultaneous accumulation of oxidised species (FAD), possibly governed by interplay between different cryptochrome molecules or cooperativity effects within the cry homodimer.
AU - van,Wilderen L
AU - Silkstone,G
AU - Mason,M
AU - van,Thor J
AU - Wilson,MT
DO - 10.1016/j.fob.2015.10.007
EP - 892
PY - 2015///
SN - 2211-5463
SP - 885
TI - Kinetic studies on the oxidation of semiquinone and hydroquinone forms of Arabidopsis cryptochrome by molecular oxygen
T2 - FEBS Open Bio
UR - http://dx.doi.org/10.1016/j.fob.2015.10.007
UR - http://hdl.handle.net/10044/1/81749
VL - 5
ER -
Join us for our Open Day on 16 May 2024 - find out more!
