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2008
Lorber B, Witz J
An Investigation of the Crystallogenesis of an Icosahedral RNA Plant Virus with Solubility Phase Diagrams Article de journal
Dans: Crystal Growth & Design, vol. 8, no. 5, p. 1522-1529, 2008, ISBN: 10.1021/cg700722b.
Résumé | Liens | BibTeX | Étiquettes: GIEGE FLORENTZ, Unité ARN
@article{,
title = {An Investigation of the Crystallogenesis of an Icosahedral RNA Plant Virus with Solubility Phase Diagrams},
author = {B Lorber and J Witz},
url = {http://pubs.acs.org/doi/abs/10.1021/cg700722b?prevSearch=[Contrib%3A+Lorber+B]&searchHistoryKey=},
isbn = {10.1021/cg700722b},
year = {2008},
date = {2008-01-01},
journal = {Crystal Growth & Design},
volume = {8},
number = {5},
pages = {1522-1529},
abstract = {The formation of crystals of the quasi-spherical tomato bushy stunt virus (TBSV, family Tombusviridae) was investigated to understand how identical cubic crystals with a dodecahedral habit grow in the presence of two chemically different precipitants, ammonium sulfate and polyethylene glycol (PEG). Two-dimensional solubility phase diagrams were established to identify the zones in which the virus crystallizes or precipitates. In the presence of the salt the solubility of the virus decreases when temperature increases. The reverse occurs in the presence of PEG. Virions stored during several years as crystals or as amorphous precipitates readily solubilize upon dilution and recrystallize under appropriate conditions like freshly purified ones. Light scattering measurements confirm that both crystallizing agents promote attractive interactions between viral particles. On a molar basis PEG-8000 is about 70-fold more effective than ammonium sulfate in insolubilizing TBSV. In the presence of each precipitant, heterogeneous nucleation takes places in a precipitate and crystal growth proceeds via an Ostwald ripening mechanism. The growth rate is controlled by the dissolution of the precipitate. Crystals with the largest dimensions always grow at apparently low supersaturation.},
keywords = {GIEGE FLORENTZ, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
The formation of crystals of the quasi-spherical tomato bushy stunt virus (TBSV, family Tombusviridae) was investigated to understand how identical cubic crystals with a dodecahedral habit grow in the presence of two chemically different precipitants, ammonium sulfate and polyethylene glycol (PEG). Two-dimensional solubility phase diagrams were established to identify the zones in which the virus crystallizes or precipitates. In the presence of the salt the solubility of the virus decreases when temperature increases. The reverse occurs in the presence of PEG. Virions stored during several years as crystals or as amorphous precipitates readily solubilize upon dilution and recrystallize under appropriate conditions like freshly purified ones. Light scattering measurements confirm that both crystallizing agents promote attractive interactions between viral particles. On a molar basis PEG-8000 is about 70-fold more effective than ammonium sulfate in insolubilizing TBSV. In the presence of each precipitant, heterogeneous nucleation takes places in a precipitate and crystal growth proceeds via an Ostwald ripening mechanism. The growth rate is controlled by the dissolution of the precipitate. Crystals with the largest dimensions always grow at apparently low supersaturation.
Lorber B
Virus and Protein Crystallization under Hypergravity Article de journal
Dans: Crystal Growth & Design, vol. 8, no. 8, p. 2964-2969, 2008, (10.1021/cg800073t).
Résumé | Liens | BibTeX | Étiquettes: GIEGE FLORENTZ, Unité ARN
@article{,
title = {Virus and Protein Crystallization under Hypergravity},
author = {B Lorber},
url = {http://pubs.acs.org/doi/abs/10.1021/cg800073t?prevSearch=%255BContrib%253A%2BLorber%2BB%255D&searchHistoryKey=},
year = {2008},
date = {2008-01-01},
journal = {Crystal Growth & Design},
volume = {8},
number = {8},
pages = {2964-2969},
abstract = {One small RNA plant virus and three monomeric and small molecular mass proteins (Mr = 14500−22200) were crystallized in a centrifuge at gravity levels between 1000 and 22000 g under conditions where controls at unit gravity are soluble. Solubility measurements indicate that all crystals have grown in solutions that are metastable, i.e., insufficiently supersaturated to nucleate under normal conditions. Upon centrifugation, particle sedimentation generates a concentration gradient. At highest local concentration, supersaturation is shifted beyond supersolubility and the critical driving force required for nucleation is overcome. A simple procedure has been implemented for sample microvolumes. The habit of protein crystals grown under hypergravity diverges from that of reference crystals but their unit cells are unchanged. Centrifugation is applicable to the crystallization of dilute samples of biological particles with a wide range of sizes, from large viruses to small proteins. It provides a means to control the onset of nucleation and in some cases to accelerate crystal growth.},
note = {10.1021/cg800073t},
keywords = {GIEGE FLORENTZ, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
One small RNA plant virus and three monomeric and small molecular mass proteins (Mr = 14500−22200) were crystallized in a centrifuge at gravity levels between 1000 and 22000 g under conditions where controls at unit gravity are soluble. Solubility measurements indicate that all crystals have grown in solutions that are metastable, i.e., insufficiently supersaturated to nucleate under normal conditions. Upon centrifugation, particle sedimentation generates a concentration gradient. At highest local concentration, supersaturation is shifted beyond supersolubility and the critical driving force required for nucleation is overcome. A simple procedure has been implemented for sample microvolumes. The habit of protein crystals grown under hypergravity diverges from that of reference crystals but their unit cells are unchanged. Centrifugation is applicable to the crystallization of dilute samples of biological particles with a wide range of sizes, from large viruses to small proteins. It provides a means to control the onset of nucleation and in some cases to accelerate crystal growth.
2007
Sauter C, Dhouib K, Lorber B
From macrofluidies to microfluidies for the crystallization of biological macromolecules Article de journal
Dans: Crystal Growth & Design, vol. 7, no. 11, p. 2247-2250, 2007, (DOI: 10.1021/cg700955f).
Résumé | Liens | BibTeX | Étiquettes: FRUGIER, GIEGE FLORENTZ, SAUTER, Unité ARN
@article{,
title = {From macrofluidies to microfluidies for the crystallization of biological macromolecules},
author = {C Sauter and K Dhouib and B Lorber},
url = {http://pubs.acs.org/doi/abs/10.1021/cg700955f?prevSearch=sauter&searchHistoryKey=},
year = {2007},
date = {2007-01-01},
journal = {Crystal Growth & Design},
volume = {7},
number = {11},
pages = {2247-2250},
abstract = {This review presents the goals and principles of microfluidic technologies applied to the crystallization of biological macromolecules. A comparison of the devices that are available commercially or described in the literature summarizes the current state-of-the-art in microfluidics. A novel chip based on the counter-diffusion of solute molecules playing the role of crystallization agents is described. Inside the microfluidic channels composing the chip mass transport essentially occurs by diffusion. The chip is made of a rigid polymer that is impermeable to gases and compatible with crystal examination and monitoring in polarized light. The selected material is also transparent to X-rays, and three-dimensional protein structures can be determined from crystals contained inside this device using X-ray diffraction data collected on a synchrotron source. The outstanding quality of the electron-density maps demonstrates that on-chip crystal analysis is feasible. The replacement of conventional crystallization setups by inexpensive microfluidic chips for screening best crystallization agents and automated crystal diffraction analysis is discussed.},
note = {DOI: 10.1021/cg700955f},
keywords = {FRUGIER, GIEGE FLORENTZ, SAUTER, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
This review presents the goals and principles of microfluidic technologies applied to the crystallization of biological macromolecules. A comparison of the devices that are available commercially or described in the literature summarizes the current state-of-the-art in microfluidics. A novel chip based on the counter-diffusion of solute molecules playing the role of crystallization agents is described. Inside the microfluidic channels composing the chip mass transport essentially occurs by diffusion. The chip is made of a rigid polymer that is impermeable to gases and compatible with crystal examination and monitoring in polarized light. The selected material is also transparent to X-rays, and three-dimensional protein structures can be determined from crystals contained inside this device using X-ray diffraction data collected on a synchrotron source. The outstanding quality of the electron-density maps demonstrates that on-chip crystal analysis is feasible. The replacement of conventional crystallization setups by inexpensive microfluidic chips for screening best crystallization agents and automated crystal diffraction analysis is discussed.
