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. 1977 Jan 15;162(1):33–38. doi: 10.1042/bj1620033

Substrate specificity of amino acid transport in sheep erythrocytes.

J D Young, J C Ellory
PMCID: PMC1164566  PMID: 849280

Abstract

The specificity of amino acid transport in normal (high-glutathione) sheep erythrocytes was investigated by studying the interaction of various neutral and dibasic amino acids in both competition and exchange experiments. Apparent Ki values were obtained for amino acids as inhibitors of L-alanine influx. Amino acids previously found to be transported by high-glutathione cells at fast rates (L-cysteine, L-alpha-amino-n-butyrate) were the most effective inhibitors. D-Alanine and D-alpha-amino-n-butyrate were without effect. Of the remaining amino acids studied, only L-norvaline, L-valine, L-norleucine, L-serine and L-2,4-diamino-n-butyrate significantly inhibited L-alanine uptake. L-Alanine efflux from pre-loaded cells was markedly stimulated by extracellular L-alanine. Those amino acids that inhibited L-alanine influx also stimulated L-alanine efflux. In addition, D-alanine, D-alpha-amino-n-biutyrate, L-threonine, L-asparagine, L-alpha, beta-diaminoproprionate, L-ornithine, L-lysine and S-2-aminoethyl-L-cysteine also significantly stimulated L-alanine efflux. L-Lysine uptake was inhibited by L-alanine but not by D-alanine, and the inhibitory potency of L-alanine was not influenced by the replacement of Na+ in the incubation medium with choline. L-Lysine efflux from pre-loaded cells was stimulated by L-alanine but not by D-alanine. It is concluded that these cells possess a highly selective stero-specific amino acid-transport system. Although the optimum substrates are small neutral amino acids, this system also has a significant affinity for dibasic amino acids.

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Selected References

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

  1. Christensen H. N., Antonioli J. A. Cationic amino acid transport in the rabbit reticulocyte. Na+-dependent inhibition of Na+-independent transport. J Biol Chem. 1969 Mar 25;244(6):1497–1504. [PubMed] [Google Scholar]
  2. Christensen H. N., Handlogten M. E., Thomas E. L. Na plus-facilitated reactions of neutral amino acids with a cationic amino acid transport system. Proc Natl Acad Sci U S A. 1969 Jul;63(3):948–955. doi: 10.1073/pnas.63.3.948. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Christensen H. N. Some special kinetic problems of transport. Adv Enzymol Relat Areas Mol Biol. 1969;32:1–20. doi: 10.1002/9780470122778.ch1. [DOI] [PubMed] [Google Scholar]
  4. DIXON M. The determination of enzyme inhibitor constants. Biochem J. 1953 Aug;55(1):170–171. doi: 10.1042/bj0550170. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Ellory J. C., Tucker E. M., Deverson E. V. The identification of ornithine and lysine at high concentrations in the red cells of sheep with an inherited deficiency of glutathione. Biochim Biophys Acta. 1972 Oct 25;279(3):481–483. doi: 10.1016/0304-4165(72)90169-9. [DOI] [PubMed] [Google Scholar]
  6. Hoare D. G. The temperature dependence of the transport of L-leucine in human erythrocytes. J Physiol. 1972 Mar;221(2):331–348. doi: 10.1113/jphysiol.1972.sp009754. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Hoare D. G. The transport of L-leucine in human erythrocytes: a new kinetic analysis. J Physiol. 1972 Mar;221(2):311–329. doi: 10.1113/jphysiol.1972.sp009753. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Thomas E. L., Shao T. C., Christensen H. N. Structural selectivity in interaction of neutral amino acids and alkali metal ions with a cationic amino acid transport system. J Biol Chem. 1971 Mar 25;246(6):1677–1681. [PubMed] [Google Scholar]
  9. Tucker E. M., Kilgour L. An inherited glutathione deficiency and a concomitant reduction in potassium concentration in sheep red cells. Experientia. 1970;26(2):203–204. doi: 10.1007/BF01895584. [DOI] [PubMed] [Google Scholar]
  10. WINTER C. G., CHRISTENSEN H. N. MIGRATION OF AMINO ACIDS ACROSS THE MEMBRANE OF THE HUMAN ERYTHROCYTE. J Biol Chem. 1964 Mar;239:872–878. [PubMed] [Google Scholar]
  11. Winter C. G., Christensen H. N. Contrasts in neutral amino acid transport by rabbit erythrocytes and reticulocytes. J Biol Chem. 1965 Sep;240(9):3594–3600. [PubMed] [Google Scholar]
  12. Young J. D., Ellory J. C., Tucker E. M. Amino acid transport defect in glutathione-deficient sheep erythrocytes. Nature. 1975 Mar 13;254(5496):156–157. doi: 10.1038/254156a0. [DOI] [PubMed] [Google Scholar]

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