Value 
100
μm^2/sec

Organism 
Generic 
Reference 
"Physical Biology of the Cell", Rob Phillips, Jane Kondev and Julie Theriot (2009). Page 110 
Method 
D calculated according to EinsteinStokes equation D=KBT/6/pi/?/R where R=2.5nm, typical protein radius. KB=Boltzmann's constant, ?(eta)=viscousity of the medium, taken as 0.001 Pa*sec for water at ~300 Kelvin, T=temperature in degrees Kelvin, pi=~3.14. (1.380?6504(24)×10^23Kgm^2 sec^2K^1×300K)/(6×3.14×0.001Kgm^1sec^1×2.5× 10^9 m)=8.8 × 10^11m^2/sec= 88µm^2sec=~100µm^2/sec 
Comments 
Radius of ~2.5 nm can be calculated by taking 100KDa and 1200 Kg/m^3 as mass and density, respectively, of typical globular protein. This gives radius of ~2.2nm. In cytoplasm D is smaller than 100µm^2/sec as there are solutes. 
Entered by 
Uri M 
ID 
104058 