Experiments performed on isolated midgut demonstrate that the model proposed for the absorption of neutral amino acids in the K+-transporting intestinal epithelium of lepidopteran larvae applies also to the transport of the basic amino acids histidine and lysine. The characteristics of these K+-basic amino-acid cotransports have been studied in brush-border membrane vesicles. Histidine and lysine are transported by different transport agencies, which share, to a different degree, a high sensitivity to transmembrane electrical potential difference. Kinetic analysis showed that Km for histidine and lysine increased 10-fold and three-fold, respectively, whereas Vmax was only slightly modified when the electrical potential difference was abolished. The relationship between potassium concentration and histidine uptake indicates a cooperative binding of more than one potassium to the transporter. Countertransport experiments with glutamine as elicitor show that histidine and glutamine are transported through the same system. © 1985 Springer-Verlag.

Giordana, B., Parenti, P., Hanozet, G., Sacchi, V. (1985). Electrogenic k+-basic amino-acid cotransport in the midgut of lepidopteran larvae. THE JOURNAL OF MEMBRANE BIOLOGY, 88(1), 45-53 [10.1007/BF01871212].

Electrogenic k+-basic amino-acid cotransport in the midgut of lepidopteran larvae

PARENTI, PAOLO;
1985

Abstract

Experiments performed on isolated midgut demonstrate that the model proposed for the absorption of neutral amino acids in the K+-transporting intestinal epithelium of lepidopteran larvae applies also to the transport of the basic amino acids histidine and lysine. The characteristics of these K+-basic amino-acid cotransports have been studied in brush-border membrane vesicles. Histidine and lysine are transported by different transport agencies, which share, to a different degree, a high sensitivity to transmembrane electrical potential difference. Kinetic analysis showed that Km for histidine and lysine increased 10-fold and three-fold, respectively, whereas Vmax was only slightly modified when the electrical potential difference was abolished. The relationship between potassium concentration and histidine uptake indicates a cooperative binding of more than one potassium to the transporter. Countertransport experiments with glutamine as elicitor show that histidine and glutamine are transported through the same system. © 1985 Springer-Verlag.
Articolo in rivista - Articolo scientifico
K+/amino acid cotransport; BBMV; membrane potential; midgut; lepidopteran larvae
English
1985
88
1
45
53
none
Giordana, B., Parenti, P., Hanozet, G., Sacchi, V. (1985). Electrogenic k+-basic amino-acid cotransport in the midgut of lepidopteran larvae. THE JOURNAL OF MEMBRANE BIOLOGY, 88(1), 45-53 [10.1007/BF01871212].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/25638
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