New experiments are revealing the power of large-scale quantum devices.
Image credit: Kavli Institute of Nanoscience, Delft University of Technology/Moritz Forsch.
New Research In
Physical Sciences
Featured Portals
Articles by Topic
Biological Sciences
Featured Portals
Articles by Topic
Edited by Robin M. Hochstrasser, University of Pennsylvania, Philadelphia, PA, and approved June 23, 2010 (received for review November 9, 2009)
Abstract
We investigated the ultrafast structural transitions of the heme induced by nitric oxide (NO) binding for several heme proteins by subpicosecond time-resolved resonance Raman and femtosecond transient absorption spectroscopy. We probed the heme iron motion by the evolution of the iron-histidine Raman band intensity after NO photolysis. Unexpectedly, we found that the heme response and iron motion do not follow the kinetics of NO rebinding. Whereas NO dissociation induces quasi-instantaneous iron motion and heme doming (< 0.6 ps), the reverse process results in a much slower picosecond movement of the iron toward the planar heme configuration after NO binding. The time constant for this primary domed-to-planar heme transition varies among proteins (∼30 ps for myoglobin and its H64V mutant, ∼15 ps for hemoglobin, ∼7 ps for dehaloperoxidase, and ∼6 ps for cytochrome c) and depends upon constraints exerted by the protein structure on the heme cofactor. This observed phenomenon constitutes the primary structural transition in heme proteins induced by NO binding.
Footnotes
- 1To whom correspondence may be addressed. E-mail: michel.negrerie{at}polytechnique.fr or sergei.kruglik{at}upmc.fr.
Author contributions: S.G.K., M.H.V., J.-L.M., and M.N. designed research; S.G.K., B.-K.Y., and M.N. performed research; S.F. contributed new reagents/analytic tools; S.G.K., B.-K.Y., S.F., M.H.V., and M.N. analyzed data; and S.G.K., M.H.V., J.-L.M., and M.N. wrote the paper.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.0912938107/-/DCSupplemental.
Picosecond primary structural transition of the heme is retarded after nitric oxide binding to heme proteins
Sign up for Article Alerts
Article Classifications
- Biological Sciences
- Biochemistry
Jump to section
You May Also be Interested in
Optimism may be an important factor for healthy aging and longevity, according to a study.
Image courtesy of iStock/Altayb.
Genetic analysis of population structure in Scotland identifies 6 genetic clusters.
Image courtesy of Pixabay/FrankWinkler.
Reconstructing the first day of the Cenozoic Era, following the asteroid impact 66 million years ago.
Image courtesy of The University of Texas at Austin Jackson School of Geosciences.
QnAs with NAS member and parasitologist Patricia Johnson
Image courtesy of Joy Ahn (University of California, Los Angeles, CA).