TY - JOUR
T1 - Ultrafast ligand binding dynamics in the active site of native bacterial nitric oxide reductase
AU - Kapetanaki, Sofia M.
AU - Field, Sarah J.
AU - Hughes, Ross J. L.
AU - Watmough, Nicholas J.
AU - Liebl, Ursula
AU - Vos, Marten H.
PY - 2008
Y1 - 2008
N2 - The active site of nitric oxide reductase from Paracoccus denitrificans contains heme and non-heme iron and is evolutionarily related to heme-copper oxidases. The CO and NO dynamics in the active site were investigated using ultrafast transient absorption spectroscopy. We find that, upon photodissociation from the active site heme, 20% of the CO rebinds in 170 ps, suggesting that not all the CO transiently binds to the non-heme iron. The remaining 80% does not rebind within 4 ns and likely migrates out of the active site without transient binding to the non-heme iron. Rebinding of NO to ferrous heme takes place in ~ 13 ps. Our results reveal that heme-ligand recombination in this enzyme is considerably faster than in heme-copper oxidases and are consistent with a more confined configuration of the active site.
AB - The active site of nitric oxide reductase from Paracoccus denitrificans contains heme and non-heme iron and is evolutionarily related to heme-copper oxidases. The CO and NO dynamics in the active site were investigated using ultrafast transient absorption spectroscopy. We find that, upon photodissociation from the active site heme, 20% of the CO rebinds in 170 ps, suggesting that not all the CO transiently binds to the non-heme iron. The remaining 80% does not rebind within 4 ns and likely migrates out of the active site without transient binding to the non-heme iron. Rebinding of NO to ferrous heme takes place in ~ 13 ps. Our results reveal that heme-ligand recombination in this enzyme is considerably faster than in heme-copper oxidases and are consistent with a more confined configuration of the active site.
U2 - 10.1016/j.bbabio.2008.03.012
DO - 10.1016/j.bbabio.2008.03.012
M3 - Article
VL - 1777
SP - 919
EP - 924
JO - Biochimica Et Biophysica Acta-Bioenergetics
JF - Biochimica Et Biophysica Acta-Bioenergetics
IS - 7-8
ER -