J. Biol. Chem., Vol. 261, Issue 26, 12154-12158, Sep, 1986
Removal of ferredoxin:NADP+ oxidoreductase from thylakoid membranes, rebinding to depleted membranes, and identification of the binding site
HC Matthijs, SJ Coughlan and G Hind
Ferredoxin-NADP+ oxidoreductase associates with thylakoid membranes into
two pools of different binding strength that are experimentally
distinguished on the basis of resistance to removal by washes in low ionic
strength media. The nondenaturing zwitterionic detergent 3-[(3-
cholamidopropyl)dimethylammonio]-1-propanesulfonic acid is uniquely able to
remove the more tightly bound pool of enzyme, without solubilization of
major membrane proteins. The reconstitution of reductase onto depleted
thylakoid membranes requires available membrane binding sites and cations,
in order of effectiveness trivalent greater than divalent greater than
monovalent. The hetero/bifunctional 125I- iodinated Denny-Jaffe
cross-linking reagent yields a 54-kDa, covalently cross-linked adduct
between ferredoxin-NADP+ oxidoreductase and a component of the thylakoid
membrane. Our results show that the more tightly bound pool of enzyme is
associated with the 17.5-kDa reductase- binding protein (Vallejos, R. H.,
Ceccarelli, E., and Chan, R. (1984) J. Biol. Chem. 259, 8048-8051).