Untitled

Hall, Robert J.

doi:10.1023/a:1016372507161

Cited by 17 publications

(4 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…8). As has been described for tubulin and actin polymerization (22,24)), and accordingly to excluded volume theory (42)(43)(44), cooperative FtsZ filament formation must also be enhanced in a crowded media due to the increase in the local FtsZ concentration in the non-excluded volume (chemical activity). The possible enhancing effect of crowding on filament formation remains nevertheless hidden, first because even in the absence of crowders they should already be present, as is indicated by the rather low value of C fil measured under these conditions (Fig.…”

Section: Crowding Promotes the Formation Of Ftsz Ribbons From Preformmentioning

confidence: 85%

Essential Cell Division Protein FtsZ Assembles into One Monomer-thick Ribbons under Conditions Resembling the Crowded Intracellular Environment

González

Jiménez

Vélez

et al. 2003

Journal of Biological Chemistry

173

227

View full text Add to dashboard Cite

Experimental conditions that simulate the crowded bacterial cytoplasmic environment have been used to study the assembly of the essential cell division protein FtsZ from Escherichia coli. In solutions containing a suitable concentration of physiological osmolytes, macromolecular crowding promotes the GTP-dependent assembly of FtsZ into dynamic two-dimensional polymers that disassemble upon GTP depletion. Atomic force microscopy reveals that these FtsZ polymers adopt the shape of ribbons that are one subunit thick. When compared with the FtsZ filaments observed in vitro in the absence of crowding, the ribbons show a lag in the GTPase activity and a decrease in the GTPase rate and in the rate of GTP exchange within the polymer. We propose that, in the crowded bacterial cytoplasm under assembly-promoting conditions, the FtsZ filaments tend to align forming dynamic ribbon polymers. In vivo these ribbons would fit into the Z-ring even in the absence of other interactions. Therefore, the presence of mechanisms to prevent the spontaneous assembly of the Z-ring in non-dividing cells must be invoked.

show abstract

Section: Crowding Promotes the Formation Of Ftsz Ribbons From Preformmentioning

confidence: 85%

Essential Cell Division Protein FtsZ Assembles into One Monomer-thick Ribbons under Conditions Resembling the Crowded Intracellular Environment

González

Jiménez

Vélez

et al. 2003

Journal of Biological Chemistry

173

227

View full text Add to dashboard Cite

show abstract

“…10 Therefore, confinement offers a new platform to be used in biophysical/biochemical studies 4 for exploring the mechanisms and kinetics of folding and unfolding of proteins in crowding. 1,11,12 Surfaces alter the molecular motions (and the physical, chemical and thermodynamic properties) 2,3,[13][14][15][16] of water in their close proximity. Therefore, when confined, the freezing temperature of water is suppressed and thus water may remain as a supercooled liquid even at cryogenic temperatures.…”

Section: Introductionmentioning

confidence: 99%

Effects of water on the structure and low/high temperature stability of confined proteins

Reátegui

Aksan

2010

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

In this study well-characterized model proteins were confined in silica nanoporous matrices. Confinement of the proteins in silica matrices allowed us to explore the role of water hydrogen bonding on the structures of the proteins in a broad range of temperatures (-120 degrees C to 95 degrees C). At low temperatures confinement suppressed freezing of water, which remained in the liquid state. We obtained direct evidence that the changes in the hydrogen bonding of water induced changes in the structure of confined proteins. At high temperatures, a reduction of hydrogen bonding of water facilitated protein-silica interactions and the confined proteins underwent denaturation. However, the incorporation of the osmolyte, trehalose, reduced protein-silica interactions, and altered the hydrogen bonding of water. As a result, the high temperature thermal stability of the confined proteins was greatly improved.

show abstract

“…For example, under certain conditions, assumptions and approximations such as the quasi-steady-state approximation break down. 7,17,18 Furthermore, numerical simulations where the available volume was varied 21 showed how variations in available space can be used to tune the thermodynamic activity of reacting species.…”

Section: Introductionmentioning

confidence: 99%

“…The deterministic approach often used so successfully in modeling reactions in simple, homogeneous, in vitro conditions is sometimes inadequate for modeling reactions in a crowded molecular environment. For example, under certain conditions, assumptions and approximations such as the quasi-steady-state approximation break down. ,, Furthermore, numerical simulations where the available volume was varied showed how variations in available space can be used to tune the thermodynamic activity of reacting species.…”

Section: Introductionmentioning

confidence: 99%

Effects of Quenched and Annealed Macromolecular Crowding Elements on a Simple Model for Signaling in T Lymphocytes

Eide

Chakraborty

2006

J. Phys. Chem. B

View full text Add to dashboard Cite

Biochemical reactions in cells occur in an environment that is crowded in the sense that various macromolecular species and organelles occupy much of the space. The effects of molecular crowding on biochemical reactions have usually been studied in the past in a spatially homogeneous environment. However, signal transduction in cells is often initiated by the binding of receptors and ligands in two apposed cell membranes, and the pertinent biochemical reactions occur in a spatially inhomogeneous environment. We have studied the effects of crowding on biochemical reactions that involve both membrane proteins and cytosolic molecules by investigating a simplified version of signaling in T lymphocytes using a Monte Carlo algorithm. We find that, if signal transduction occurs on time scales that are slow compared to the motility of the molecules and organelles that constitute the crowding elements, the effects of crowding are qualitatively the same as in a homogeneous three-dimensional (3D) medium. In contrast, if signal transduction occurs on a time scale that is much faster than the time over which the crowding elements move, then the effects of varying the extent of crowding are very different when reactions occur in both 2- and 3D space. We discuss these differences and their origin. Since many signaling reactions are fast, our results may be useful for diverse situations in cell biology.

show abstract

Untitled

Cited by 17 publications

References 28 publications

Essential Cell Division Protein FtsZ Assembles into One Monomer-thick Ribbons under Conditions Resembling the Crowded Intracellular Environment

Essential Cell Division Protein FtsZ Assembles into One Monomer-thick Ribbons under Conditions Resembling the Crowded Intracellular Environment

Effects of water on the structure and low/high temperature stability of confined proteins

Effects of Quenched and Annealed Macromolecular Crowding Elements on a Simple Model for Signaling in T Lymphocytes

Contact Info

Product

Resources

About