Effect of temperature on the diffusion coefficient of BODIPY FL-C12 (a green fluorescent fatty acid derivative)

Range 15°C-25°C ~0.6μm^2/sec: 30°C-37°C ~1.2μm^2/sec μm^2/sec
Organism Bacteria Escherichia coli
Reference Nenninger A et al., Independent mobility of proteins and lipids in the plasma membrane of Escherichia coli. Mol Microbiol. 2014 Jun92(5):1142-53. doi: 10.1111/mmi.12619. p.1145 fig.4PubMed ID24735432
Method Abstract: "Here [investigators] report lipid and protein diffusion in the plasma membrane of live cells of the bacterium Escherichia coli, using Fluorescence Recovery after Photobleaching (FRAP) and Total Internal Reflection Fluorescence (TIRF) microscopy to measure lateral diffusion coefficients. Lipid and protein mobility within the membrane were probed by visualizing an artificial fluorescent lipid and a simple model membrane protein consisting of a single membrane-spanning alpha-helix with a Green Fluorescent Protein (GFP) tag on the cytoplasmic side." Values extracted visually from fig.4
Comments P.1145 left column bottom paragraph: "Effect of temperature on the mobility of BODIPY FL-C12: The green fluorescent fatty acid derivative BODIPY FL-C12 has previously been used as a probe of the fluidity of thylakoid membranes in cyanobacteria, where there is a pronounced dependence of its diffusion coefficient on temperature and the extent of fatty acid desaturation in the membrane (Sarcina et al., 2003). [Investigators] used confocal FRAP to measure the diffusion of BODIPY FL-C12 in the cytoplasmic membrane of E. coli as a function of temperature, for cells grown at 37°C. Supplementary Fig. S2 shows a representative measurement with data analysis. When cells were cooled [they] observed a step decrease in the lateral diffusion coefficient at about 28°C (Fig. 4). This resembles a classic phase transition from the liquid crystal to the crystalline gel states of the lipid bilayer, which in biological membranes usually occurs around 5–10°C below growth temperature (Hazel and Williams, 1990). However, as the E. coli cytoplasmic membrane is a very complex mixture of lipids and proteins, [they] cannot exclude the possibility that the change in BODIPY FL-C12 mobility is due to effects other than a simple lipid phase transition." See note beneath figure
Entered by Uri M
ID 112470