Diffusion coefficient of microRNA in cell

Value 10 µm^2/sec
Organism Generic
Reference Zhdanov VP. Conditions of appreciable influence of microRNA on a large number of target mRNAs. Mol Biosyst. 2009 Jun5(6):638-43 p.641 left column top paragraphPubMed ID19462021
Method According to hydrodynamics, the coefficient of diffusion of spherically shaped particles in water is given by D=KBT/6/p/?/R , where R is the particle radius, and ? is the viscosity. For miRNA (or folded proteins), R is about 2×10^-9m. Using this value and ?=0.01g/cm/sec=0.001kg/m/sec, (1.380?6504(24)×10^-23Kg× m^2×sec^-2×K^-1×300K)/ (6×3.14×0.001Kg×m^-1sec^-1×2×10^-9m)=1.1×10^-10m^2/sec =110µm^2/sec˜100µm^2/sec. Inside cells, the diffusion coefficient is, however, lower by about one order of magnitude (Misteli 2008 PMID 17994245) due to macromolecular crowding resulting in steric constraints on diffusion and influencing diffusion via weak intermolecular interactions, i.e., D=10µm^2/sec.
Entered by Uri M
ID 105180