Open AccessRole of critical charged residues in reduction potential modulation of ferredoxin‐NADP + reductase
Author(s) -
Faro Merche,
GómezMoreno Carlos,
Stankovich Marian,
Medina Milagros
Publication year - 2002
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1046/j.1432-1033.2002.02925.x
Subject(s) - ferredoxin , flavin group , cofactor , ferredoxin—nadp(+) reductase , reductase , electron transfer , chemistry , flavin adenine dinucleotide , stereochemistry , biochemistry , photochemistry , enzyme
Reduction potential determinations of K75E, E139K and E301A ferredoxin‐NADP + reductases provide valuable information concerning the factors that contribute to tune the flavin reduction potential. Thus, while E139 is not involved in such modulation, the K75 side‐chain tunes the flavin potential by creating a defined environment that modulates the FAD conformation. Finally, the E301 side‐chain influences not only the flavin reduction potential, but also the electron transfer mechanism, as suggested from the values determined for the E301A mutant, where E ox/rd and E sq/rd shifted +41 and +102 mV, respectively, with regard to wild‐type. Reduction potentials allowed estimation of binding energies differences of the FAD cofactor upon reduction.