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. 1981 May;146(2):676–683. doi: 10.1128/jb.146.2.676-683.1981

Toxicity of leucine-containing peptides in Escherichia coli caused by circumvention of leucine transport regulation.

H Tavori, Y Kimmel, Z Barak
PMCID: PMC217012  PMID: 7012134

Abstract

A variety of leucine-containing peptides (LCP), Phe-Leu, Gly-Leu, Pro-Leu, Ala-Leu, Ala-Leu-Lys, Leu-Phe-Ala, Leu-Leu-Leu, and Leu-Gly-Gly, inhibited the growth of a prototrophic strain of Escherichia coli K-12 at concentrations between 0.05 and 0.28 mM. Toxicity requires normal uptake of peptides. When peptide transport was impaired by mutations, strains became resistant to the respective LCP. Inhibition of growth occurred immediately after the addition of LCP, and was relieved when 0.4 mM isoleucine was added. The presence of Gly-Leu in the medium correlated with the inhibition of growth, and the bacteria began to grow at the normal rate 70 min after Gly-Leu became undetectable. Disappearance of the peptide corresponded with the appearance of free leucine and glycine in the medium. The concentration of leucine inside the LCP-treated bacteria was higher than that in the leucine-treated and the control cultures. We suggest that entry of LCP into the cells via peptide transport systems circumvents the regulation of leucine transport, thereby causing abnormality high concentrations of leucine inside the cells. This accumulation of leucine interferes with the biosynthesis of isoleucine and inhibits the growth of the bacteria.

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Selected References

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  1. Barak Z., Gilbarg C. Specialized peptide transport system in Escherichia coli. J Bacteriol. 1975 Jun;122(3):1200–1207. doi: 10.1128/jb.122.3.1200-1207.1975. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Barak Z., Gilvarg C. Peptide transport. Biomembranes. 1975;7:167–218. doi: 10.1007/978-1-4684-7668-2_7. [DOI] [PubMed] [Google Scholar]
  3. Blatt J. M., Pledger W. J., Umbarger H. E. Isoleucine and valine metabolism in Escherichia coli. XX. Multiple forms of acetohydroxy acid synthetase. Biochem Biophys Res Commun. 1972 Jul 25;48(2):444–450. doi: 10.1016/s0006-291x(72)80071-8. [DOI] [PubMed] [Google Scholar]
  4. Calhoun D. H. Threonine deaminase from Escherichia coli: feedback-hypersensitive enzyme from a genetic regulatory mutant. J Bacteriol. 1976 Apr;126(1):56–63. doi: 10.1128/jb.126.1.56-63.1976. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. De Felice M., Guardiola J., Lamberti A., Iaccarino M. Escherichia coli K-12 mutants altered in the transport systems for oligo- and dipeptides. J Bacteriol. 1973 Nov;116(2):751–756. doi: 10.1128/jb.116.2.751-756.1973. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. De Felice M., Levinthal M. The acetohydroxy acid synthase III isoenzyme of Escherichia coli K-12: regulation of synthesis by leucine. Biochem Biophys Res Commun. 1977 Nov 7;79(1):82–87. doi: 10.1016/0006-291x(77)90063-8. [DOI] [PubMed] [Google Scholar]
  7. Guardiola J., De Felice M., Klopotowski T., Iaccarino M. Multiplicity of isoleucine, leucine, and valine transport systems in Escherichia coli K-12. J Bacteriol. 1974 Feb;117(2):382–392. doi: 10.1128/jb.117.2.382-392.1974. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Naider F., Becker J. M. Multiplicity of oligopeptide transport systems in Escherichia coli. J Bacteriol. 1975 Jun;122(3):1208–1215. doi: 10.1128/jb.122.3.1208-1215.1975. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Payne J. W., Gilvarg C. The role of the terminal carboxyl group on peptide transport in Escherichia coli. J Biol Chem. 1968 Jan 25;243(2):335–340. [PubMed] [Google Scholar]
  10. Quay S. C., Dick T. E., Oxender D. L. Role of transport systems in amino acid metabolism: leucine toxicity and the branched-chain amino acid transport systems. J Bacteriol. 1977 Mar;129(3):1257–1265. doi: 10.1128/jb.129.3.1257-1265.1977. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Quay S. C., Oxender D. L. Regulation of branched-chain amino acid transport in Escherichia coli. J Bacteriol. 1976 Sep;127(3):1225–1238. doi: 10.1128/jb.127.3.1225-1238.1976. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Rahmanian M., Claus D. R., Oxender D. L. Multiplicity of leucine transport systems in Escherichia coli K-12. J Bacteriol. 1973 Dec;116(3):1258–1266. doi: 10.1128/jb.116.3.1258-1266.1973. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. SIMMONDS S., HARRIS J. I., FRUTON J. S. Inhibition of bacterial growth by leucine peptides. J Biol Chem. 1951 Jan;188(1):251–262. [PubMed] [Google Scholar]
  14. Tully M., Yudkin M. D. Fine-structure mapping and complementation analysis of the Escherichia coli cysB gene. J Bacteriol. 1977 Jul;131(1):49–56. doi: 10.1128/jb.131.1.49-56.1977. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Umbarger H. E. Amino acid biosynthesis and its regulation. Annu Rev Biochem. 1978;47:532–606. doi: 10.1146/annurev.bi.47.070178.002533. [DOI] [PubMed] [Google Scholar]
  16. VOGEL H. J., BONNER D. M. Acetylornithinase of Escherichia coli: partial purification and some properties. J Biol Chem. 1956 Jan;218(1):97–106. [PubMed] [Google Scholar]
  17. Vonder Haar R. A., Umbarger H. E. Isoleucine and valine metabolism in Escherichia coli. XIX. Inhibition of isoleucine biosynthesis by glycyl-leucine. J Bacteriol. 1972 Oct;112(1):142–147. doi: 10.1128/jb.112.1.142-147.1972. [DOI] [PMC free article] [PubMed] [Google Scholar]

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