Supported by grants from the National Science Center and the Ministry of Science and Higher Education as well as by programs from the Foundation for Polish Science, the research published in the "Bioinformatics" journal focused on the rate of diffusion of protein molecules in the Escherichia coli cytoplasm.
"The viscosity inside mammalian cells is relatively low, only 60 times higher than that of water. But bacteria are considerably smaller, everything is more crowded. The macroscopic viscosity there is up to 26,000 times higher than that of water. This is really dramatic difference!", concludes Dr Tomasz Kalwarczyk (IPC PAS).
Earlier research of Prof. Hołyst's team allowed for concluding that viscosity experienced by molecules is not only medium, i.e., solvent dependent, but also depends on the size and shape of molecules. Therefore, in the same medium, molecules differing in shape and size can experience very low viscosity (nanoviscosity) or macroscopic viscosity that is up to several thousand times higher. The previous methods for predicting diffusion coefficients in cytoplasm have not accounted for the effect.
Experimental determination of the diffusion rates of chemical compounds in bacterial cells is both time consuming and difficult. As a result, diffusion coefficients have been measured only for a very limited number of compounds in only some bacterial cells. That's why the researchers from the IPC PAS developed a method for predicting diffusion coefficients for various compounds and media. For that purpose they used their own formulae, accounting for nanovisco
|Contact: Robert Hoyst|
Institute of Physical Chemistry of the Polish Academy of Sciences