Electrical and chemical components of the pmf (proton motive force, given an external pH of 7.0 and a cytoplasmic pH of 7.6)

Range ∆ψ≈-115 mV: -59∆pH≈35mV mV
Organism Bacteria Escherichia coli
Reference Gabel CV, Berg HC. The speed of the flagellar rotary motor of Escherichia coli varies linearly with protonmotive force. Proc Natl Acad Sci U S A. 2003 Jul 22 100(15):8748-51. p.8750 right column 3rd paragraphPubMed ID12857945
Primary Source 9. Navon G, Ogawa S, Shulman RG, Yamane T. High-resolution 31P nuclear magnetic resonance studies of metabolism in aerobic Escherichia coli cells. Proc Natl Acad Sci U S A. 1977 Mar74(3):888-91. & 10. Slonczewski JL, Rosen BP, Alger JR, Macnab RM. pH homeostasis in Escherichia coli: measurement by 31P nuclear magnetic resonance of methylphosphonate and phosphate. Proc Natl Acad Sci U S A. 1981 Oct78(10):6271-5.PubMed ID15257, 7031646
Comments "[Researchers'] measurements show that, for a given viscous load, the motor’s rotation rate remains proportional to the cell’s pmf regardless of speed. They do not, however, discern between the electrical and chemical components of the pmf (which are initially about ??=-115mV and -59?pH=35 mV respectively, given an external pH of 7.0 and a cytoplasmic pH of 7.6) (primary sources)."
Entered by Uri M
ID 109819