The regulation of the properties of Desulfovibrio gigas flavodoxin in
AOT/water/iso-octane micellar system was studied. UV-visible spectrosc
opic studies have shown that photoreduction of flavodoxin in the prese
nce of EDTA leads to hydroquinone formation through the intermediate s
emiquinone. The [free FMN] - [bound to flavodoxin PMN] equilibrium (an
d hence, the amount of apoprotein) depends on redox state of FMN and o
n hydration degree which controls the micellar size. Thus, a new metho
d of reversible cofactor removing under mild conditions (at low hydrat
ion degree of micelles) is suggested, accompained by isolation of apo-
form of the protein. (C) 1997 Academic Press.