Complex landscape of protein structural dynamics unveiled by nanosecond Laue crystallography

@article{Bourgeois2003ComplexLO,
  title={Complex landscape of protein structural dynamics unveiled by nanosecond Laue crystallography},
  author={D. Bourgeois and B. Vallone and F. Schotte and A. Arcovito and A. Miele and G. Sciara and M. Wulff and P. Anfinrud and M. Brunori},
  journal={Proceedings of the National Academy of Sciences of the United States of America},
  year={2003},
  volume={100},
  pages={8704 - 8709}
}
Although conformational changes are essential for the function of proteins, little is known about their structural dynamics at atomic level resolution. Myoglobin (Mb) is the paradigm to investigate conformational dynamics because it is a simple globular heme protein displaying a photosensitivity of the iron–ligand bond. Upon laser photodissociation of carboxymyoglobin Mb a nonequilibrium population of protein structures is generated that relaxes over a broad time range extending from… Expand
Extended subnanosecond structural dynamics of myoglobin revealed by Laue crystallography.
TLDR
Subnanosecond time-resolved Laue diffraction data on the triple mutant YQR-Mb depict the sequence of structural events associated with heme and protein relaxation from 100 ps to 316 ns and above, suggesting that the internal structure controls the rate and amplitude of the relaxation events. Expand
The structural dynamics of myoglobin.
TLDR
The extended relaxation of the globin moiety directly observed by Laue crystallography reflects re-equilibration among conformational substates known to play an essential role in controlling protein function. Expand
Picosecond time-resolved X-ray crystallography: probing protein function in real time.
TLDR
This work reports the photolysis-induced structural evolution of wild-type and L29F myoglobin over times ranging from 100 ps to 3 micros, and develops a novel method for rendering time-resolved electron density that depicts motion as a color gradient across the atom or group of atoms that move. Expand
Unveiling functional protein motions with picosecond x-ray crystallography and molecular dynamics simulations.
TLDR
Ensemble-averaged MD simulations of the L29F mutant of myoglobin after ligand dissociation reproduce the direction, amplitude, and time scales of crystallographically determined structural changes, and suggest how picosecond protein motions modulate the functional dissociation of oxygen and suppress the geminate recombination of toxic carbon monoxide. Expand
Human myoglobin recognition of oxygen: Dynamics of the energy landscape
TLDR
This work proposes a “bifurcation model” for populations of directed and undirected dynamics on the ultrafast time scale, reflecting the distribution of initial protein conformations, and finds the major mutation effect occurs on the time scale on which global protein conformational change is possible. Expand
Ligand migration pathway and protein dynamics in myoglobin: a time-resolved crystallographic study on L29W MbCO.
TLDR
By using time-resolved x-ray crystallography at room temperature, structural relaxations and ligand migration were examined in myoglobin (Mb) mutant L29W from nanoseconds to seconds after photodissociation of carbon monoxide (CO) from the heme iron by Nanosecond laser pulses, thus allowing a quantitative description of the processes involved. Expand
Femtosecond Structural Dynamics of Proteins
Proteins are the workhorses of living cells, providing essential functions such as structural support, signal transduction, enzymatic catalysis, transport and storage of small ligands.Expand
Structural dynamics of myoglobin.
TLDR
This chapter describes some of the technological features involved in obtaining reliable data by time-resolved Laue crystallography, with subnanosecond time resolution. Expand
Dipar Institu Synch Structural Dynamics of Myoglobin
Protein structure is endowed with a complex dynamic nature, which rules function and controls activity. The experimental investigations that yield information on protein dynamics are carried out inExpand
Allosteric action in real time: Time-resolved crystallographic studies of a cooperative dimeric hemoglobin
TLDR
This study provides a view of structural changes in single crystals of Scapharca dimeric hemoglobin as they proceed in real time, from 5 ns to 80 μs after ligand photodissociation, suggesting a slow T-to-R transition. Expand
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 58 REFERENCES
Nonexponential protein relaxation: dynamics of conformational change in myoglobin.
The picosecond evolution of the tertiary conformation of myoglobin (Mb) after photodissociation of MbCO was investigated at room temperature by probing band III, a weak iron-porphyrin charge-transferExpand
Ligand binding and conformational motions in myoglobin
TLDR
It is shown that below 180 K photodissociated ligands migrate to specific sites within an internal cavity—the distal haem pocket— of an essentially immobilized, frozen protein, from where they subsequently rebind by thermally activated barrier crossing. Expand
Structural dynamics of ligand diffusion in the protein matrix: A study on a new myoglobin mutant Y(B10) Q(E7) R(E10).
TLDR
The hypothesis may rationalize the O2 binding properties of Mb-YQR and more generally to propose a mechanism of control of ligand binding and dissociation in hemeproteins based on the dynamics of side chains that may allow access to and direct temporary sequestration of the dissociated ligand in a docking site within the protein. Expand
Cavities and packing defects in the structural dynamics of myoglobin
TLDR
Results convey the general picture that pre‐existing internal cavities are involved in controlling the dynamics and reactivity of the reactions of Mb with O2 and other ligands, including NO. Expand
The role of cavities in protein dynamics: crystal structure of a photolytic intermediate of a mutant myoglobin.
TLDR
The experiment shows that the pathway of a small molecule in its trajectory through a protein may be modified by site-directed mutagenesis, and that migration within the protein matrix to the active site involves a limited number of pre-existing cavities identified in the interior space of the protein. Expand
Ligand binding to heme proteins: connection between dynamics and function.
TLDR
The results show that protein dynamics is essential for protein function and that the association coefficient for binding from the solvent at physiological temperatures in all these heme proteins is governed by the barrier at the heme. Expand
Protein conformational relaxation and ligand migration in myoglobin: a nanosecond to millisecond molecular movie from time-resolved Laue X-ray diffraction.
TLDR
These results demonstrate that structural changes as small as 0.2 A and populations of CO docking sites of 10% can be detected by time-resolved X-ray diffraction. Expand
Conformational relaxation and ligand binding in myoglobin.
TLDR
Ex extrapolation of the data to temperatures near that of the solvent glass transition suggests that this conformational relaxation may very well be the one postulated by Frauenfelder and co-workers to explain the decrease in the rate of geminate rebinding with increasing temperature above 180 K. Expand
Crystal structure of photolysed carbonmonoxy-myoglobin
TLDR
X-ray crystallography at liquid-helium temperatures is used to determine the structure of Mb*CO to a resolution of 1.5 Å and reveals that on photodissociation of the CO, the haem 'domes', the iron moves partially out of the haems plane, the iron–proximal histidine bond is compressed, the F helix is strained and the distal histidine swings towards the outside of the ligand-binding pocket. Expand
Structural Dynamics of Myoglobin
TLDR
FTIR spectroscopy in the CO stretch bands combined with TDS was used to characterize intermediate states obtained by photolysis of two sperm whale mutant myoglobins, supporting the view that the return of the ligand from the C′, C′′, and D states is not governed by the recombination barrier at the heme iron but rather by migration to the active site. Expand
...
1
2
3
4
5
...