ISSN:
1573-6881
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Physics
Notes:
Abstract The formation of membrane potential in energizedE. coli cells has been investigated by means of ionic penetrants. The fluxes of anions and cations in opposite directions have been observed: anions moved out and cations moved into the cells. The energy-linked uptake of cations was stoichiometrically coupled with the outflow of H+ ions from the cells. The value of a membrane potential in the energized cells calculated from a distribution of permanent cations was in the range of −140mV (inside minus). The uptake of penetrating cations by deenergized cells has been observed following the non-enzymatic generation of a membrane potential. The influx of synthetic and natural (lactose) penetrants collapsed the non-enzymatic membrane potential. The effect of lactose was sensitive to N-ethyl maleimide. These results are in favour of the conception that in the energizedE. coli cells an energy-linked H+-pump generates a membrane potential which is a driving force for the transport of synthetic and some natural penetrants.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01558460
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