Assymetry of the myo-inositol transport system in Klebsiella aerogenes. Energy is necessary to create the assymetry of the transport system.
1. In Klebsiella aerogenes the influx of myo-inositol proceeds during the steady state at a rate equal to that of efflux. 2. The kinetic parameters of influx during the steady state are similar to those observed at the initial time of uptake. 3. Efflux and influx processes share the same transport system. 4. The ability of other cyclitols to chase the accumulated scyllo-inositol is dependent on their affinity for the transport system. 5. A counter transport can be observed in preloaded cells only in poisoned cells and under anaerobiosis. 6. The efflux process is not temperature-dependent. 7. The KT of influx in poisoned cells is larger than that in normal cells. 8. Although no saturation kinetics of efflux could be observed, it can be inferred that the KT of efflux is at least 50-fold larger than the KT of influx; 9. The results suggest that in the transport of myo-inositol by K. aerogenes energy coupling enhances the affinity of the carrier for the substrate at the outer side of the cytolplasmic membrane by lowering the KT.
D000332:Aerobiosis; D000693:Anaerobiosis; D001386:Azides / Q000494:pharmacology; D001692:Biological Transport; D001693:Biological Transport, Active; D003486:Cyanides / Q000494:pharmacology; D004140:Dinitrophenols / Q000494:pharmacology; D005033:Ethylmaleimide / Q000494:pharmacology; D006902:Hydroxymercuribenzoates / Q000494:pharmacology; D007294:Inositol / Q000378:metabolism*; D007536:Isomerism; D007700:Kinetics; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000378:metabolism*; D013329:Structure-Activity Relationship
D001386:Azides; D003486:Cyanides; D004140:Dinitrophenols; D006902:Hydroxymercuribenzoates; D007294:Inositol; D005033:Ethylmaleimide