Article
Folate transport by prawn hepatopancreas brush-border membrane vesicles.
Author/s | Blaya, J. A.
Muriana, Francisco J. G. Ruiz Gutiérrez, Valentina Vázquez Cueto, Carmen María Bolufer González, José |
Department | Universidad de Sevilla. Departamento de Fisiología |
Publication Date | 1998 |
Deposit Date | 2015-09-23 |
Published in |
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Abstract | The transport system of folic acid (Pte-Glu) b y brush-borde r membrane vesicles (BBMV ) isolated from prawn (Penaeus japonicm) hepatopancreas , was studied by measuring the uptake of Pte-Glu . This uptake was found to ... The transport system of folic acid (Pte-Glu) b y brush-borde r membrane vesicles (BBMV ) isolated from prawn (Penaeus japonicm) hepatopancreas , was studied by measuring the uptake of Pte-Glu . This uptake was found to have two components , intravesicular transport and membrane binding . Membrane binding was not affected by the presence of a trans - membrane pH-gradient at a short incubation period . However , a transmembrane pH - gradient increased membrane binding at 6 0 min. The transpor to f Pte-Glu appeared to be carrier-mediated , was stimulated by an inwardly proton gradient (p H 5. 5 outside , 7. 4 inside ) and was unaffected by a sodium-gradient . The relationship between pH gradient-driven Pte-Glu uptake and medium Pte-Glu concentration followed saturating Michaelis-Menten kinetics . Eadie-Hofste e representation of the pH gradient-driven Pte-Glu uptake indicated a single transport system with a Km of 0.3 7 ^ Man d Vmax of 1.06pmol/mg protein/15s . These findings indicate that BBM V isolated from prawn hepatopancreas possesses a Pte - Glu transport system similar to that described in mammalian intestine. |
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