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Echinococcus granulosus: specificity of amino acid transport systems in protoscoleces

Published online by Cambridge University Press:  06 April 2009

S. A. Jeffs  and
C. Arme
S. A. Jeffs
Affiliation:
Parasitology Research Laboratory, University of Keele, Keele, Staffs ST5 5BG
C. Arme
Affiliation:
Parasitology Research Laboratory, University of Keele, Keele, Staffs ST5 5BG
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Summary

Protoscoleces of Echinococcus granulosus absorb the l-amino acids proline, methionine, leucine, alanine, serine, phenylalanine, lysine and glutamic acid by a combination of mediated transport and diffusion. All eight amino acids were accumulated against a concentration gradient. Comparison of Kt and Vmax values suggests that a low affinity for a particular compound is compensated for by a relatively larger number of transport sites for that compound. Four systems serve for the transport of the eight substrates studied: 2 for neutral (EgNl, EgN2) and 1 each for acidic (EgA) and basic (EgB) amino acids. All eight amino acids are incorporated into protein to varying degrees and substantial portions of absorbed l-alanine and l-methionine are metabolized into other compounds.

Type
Research Article
Information
Parasitology , Volume 95 , Issue 1 , August 1987 , pp. 71 - 78
Copyright
Copyright © Cambridge University Press 1987

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