| Value |
0.014
µm^2/sec
|
| Organism |
Bacteria Escherichia coli |
| Reference |
Mika JT, Poolman B. Macromolecule diffusion and confinement in prokaryotic cells. Curr Opin Biotechnol. 2011 Feb22(1):117-26. doi: 10.1016/j.copbio.2010.09.009 p.120 left column top paragraphPubMed ID20952181
|
| Primary Source |
[15] Konopka MC, Shkel IA, Cayley S, Record MT, Weisshaar JC. Crowding and confinement effects on protein diffusion in vivo. J Bacteriol. 2006 Sep188(17):6115-23 DOI: 10.1128/JB.01982-05PubMed ID16923878
|
| Method |
Abstract: "[Investigators] review recent observations on the mobility of macromolecules and their spatial organization in live bacterial cells. [They] outline the major fluorescence microscopy-based methods to determine the mobility and thus the diffusion coefficients (D) of molecules, which is not trivial in small cells." Primary source abstract: "The first in vivo measurements of a protein diffusion coefficient versus cytoplasmic biopolymer volume fraction are presented. Fluorescence recovery after photobleaching yields the effective diffusion coefficient on a 1-mum-length scale of green fluorescent protein within the cytoplasm of Escherichia coli grown in rich medium. Resuspension into hyperosmotic buffer lacking K+ and nutrients extracts cytoplasmic water, systematically increasing mean biopolymer volume fraction, <phi>, and thus the severity of possible crowding, binding, and confinement effects." |
| Comments |
P.120 left column top paragraph: "Konopka reports that in osmotically upshifted cells (ΔOsm = 0.7, equivalent to a medium supplement of 400 mM NaCl) cytoplasmic diffusion of GFP is reduced to 0.014 μm^2/s [primary source], which is two orders of magnitude slower than in cells at typical osmotic conditions of ∼0.44 Osm." |
| Entered by |
Uri M |
| ID |
116045 |