Skip to main content
NCBI home page
Journal of Bacteriology logoLink to Journal of Bacteriology
. 1983 Apr;154(1):92–103. doi: 10.1128/jb.154.1.92-103.1983

Comparison of lactose uptake in resting and energized Escherichia coli cells: high rates of respiration inactivate the lac carrier.

A Ghazi, H Therisod, E Shechter
PMCID: PMC217435  PMID: 6403513

Abstract

The transport of lactose by Escherichia coli cells was radically different in the absence and in the presence of an exogenous energy source: in the former case, the time course of lactose accumulation was monotonous; in the latter case, lactose accumulation reached a maximum and then decreased to a final steady-state level lower than that observed in the absence of an energy source. We show that this "overshoot" is the result of a decrease in the influx rate and of an increase in the rate constant of efflux as lactose accumulates. These phenomena were irreversible. The extent of the overshoot was dependent upon the experimental conditions: it was maximal at alkaline pH, for low external potassium concentrations, and for relatively high external lactose concentrations (around or above the KT of uptake). The addition of an energy source to resting E. coli cells resulted in an increase in both the electrochemical gradient of protons and in the rate of respiration. We demonstrate that the overshoot is the result of the latter and unrelated to the former. We observed an irreversible decrease in the membrane potential as lactose accumulated in the presence of an exogenous energy source. We discuss the whole of our data in terms of an irreversible inactivation of the lactose carrier as a result of a possible interaction with the respiratory chain.

Full text

PDF
92

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. BUTTIN G., COHEN G. N., MONOD J., RICKENBERG H. V. La galactoside-perméase d'Escherichia coli. Ann Inst Pasteur (Paris) 1956 Dec;91(6):829–857. [PubMed] [Google Scholar]
  2. Booth I. R., Mitchell W. J., Hamilton W. A. Quantitative analysis of proton-linked transport systems. The lactose permease of Escherichia coli. Biochem J. 1979 Sep 15;182(3):687–696. doi: 10.1042/bj1820687. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Büchel D. E., Gronenborn B., Müller-Hill B. Sequence of the lactose permease gene. Nature. 1980 Feb 7;283(5747):541–545. doi: 10.1038/283541a0. [DOI] [PubMed] [Google Scholar]
  4. COHEN G. N., MONOD J. Bacterial permeases. Bacteriol Rev. 1957 Sep;21(3):169–194. doi: 10.1128/br.21.3.169-194.1957. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Dykhuizen D., Hartl D. Transport by the lactose permease of Escherichia coli as the basis of lactose killing. J Bacteriol. 1978 Sep;135(3):876–882. doi: 10.1128/jb.135.3.876-882.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Ghazi A., Shechter E. Lactose transport in Escherichia coli cells. Dependence of kinetic parameters on the transmembrane electrical potential difference. Biochim Biophys Acta. 1981 Jun 22;644(2):305–315. doi: 10.1016/0005-2736(81)90388-6. [DOI] [PubMed] [Google Scholar]
  7. Kaback H. R. Molecular biology and energetics of membrane transport. J Cell Physiol. 1976 Dec;89(4):575–593. doi: 10.1002/jcp.1040890414. [DOI] [PubMed] [Google Scholar]
  8. Kell D. B. On the functional proton current pathway of electron transport phosphorylation. An electrodic view. Biochim Biophys Acta. 1979 Jul 3;549(1):55–99. doi: 10.1016/0304-4173(79)90018-1. [DOI] [PubMed] [Google Scholar]
  9. Kroll R. G., Booth I. R. The role of potassium transport in the generation of a pH gradient in Escherichia coli. Biochem J. 1981 Sep 15;198(3):691–698. doi: 10.1042/bj1980691. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Newman M. J., Foster D. L., Wilson T. H., Kaback H. R. Purification and reconstitution of functional lactose carrier from Escherichia coli. J Biol Chem. 1981 Nov 25;256(22):11804–11808. [PubMed] [Google Scholar]
  11. Osumi T., Saier M. H., Jr Regulation of lactose permease activity by the phosphoenolpyruvate:sugar phosphotransferase system: evidence for direct binding of the glucose-specific enzyme III to the lactose permease. Proc Natl Acad Sci U S A. 1982 Mar;79(5):1457–1461. doi: 10.1073/pnas.79.5.1457. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Therisod H., Ghazi A., Houssin C., Shechter E. Lactose transport in Escherichia coli cells. Evidence in favor of a permease-catalyzed efflux of lactose without protons. FEBS Lett. 1982 Apr 19;140(2):181–184. doi: 10.1016/0014-5793(82)80889-2. [DOI] [PubMed] [Google Scholar]
  13. Wilson D. M., Putzrath R. M., Wilson T. H. Inhibition of growth of Escherichia coli by lactose and other galactosides. Biochim Biophys Acta. 1981 Dec 7;649(2):377–384. doi: 10.1016/0005-2736(81)90427-2. [DOI] [PubMed] [Google Scholar]
  14. Wright J. K., Schwarz H., Straub E., Overath P., Bieseler B., Beyreuther K. Lactose carrier protein of Escherichia coli. Reconstitution of galactoside binding and countertransport. Eur J Biochem. 1982 Jun;124(3):545–552. doi: 10.1111/j.1432-1033.1982.tb06628.x. [DOI] [PubMed] [Google Scholar]
  15. Yamasaki K., Moriyama Y., Futai M., Tsuchiya T. Uptake and extrusion of k+ regulated by extracellular pH in Escherichia coli. FEBS Lett. 1980 Oct 20;120(1):125–127. doi: 10.1016/0014-5793(80)81061-1. [DOI] [PubMed] [Google Scholar]
  16. Zilberstein D., Schuldiner S., Padan E. Proton electrochemical gradient in Escherichia coli cells and its relation to active transport of lactose. Biochemistry. 1979 Feb 20;18(4):669–673. doi: 10.1021/bi00571a018. [DOI] [PubMed] [Google Scholar]

Articles from Journal of Bacteriology are provided here courtesy of American Society for Microbiology (ASM)

RESOURCES