Kinetic characterization of apical D-fructose transport in chicken jejunum
| Autor: | A. Barfull, Juana M. Planas, Carles Garriga |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Male
Monosaccharide Transport Proteins Physiology Phlorizin Phloretin Biophysics Biological Transport Active Fructose Jejunum chemistry.chemical_compound medicine Animals Cytochalasin Cytochalasin B Cells Cultured biology Microvilli Glucose Transporter Type 5 Glucose transporter Cell Biology Small intestine Kinetics medicine.anatomical_structure Enterocytes Biochemistry chemistry biology.protein GLUT5 Chickens |
| Zdroj: | The Journal of membrane biology. 197(1) |
| ISSN: | 0022-2631 |
| Popis: | In mammals, D-fructose transport takes place across the brush-border membrane of the small intestine through GLUT5, a member of the facilitative glucose transporter family. In the present paper, we describe and characterize for the first time the apical transport of D-fructose in chicken intestine. Brush-border membrane vesicles (BBMV) were obtained from jejunum of 5- to 6-wk-old chickens. D-Fructose uptake by BBMV from chicken jejunum comprises a saturable component and a simple diffusion process. The maximal rate of transport (V max) for D-fructose was 2.49 nmol·(mg prot)−1·s−1, the Michaelis constant (K m) was 29 mM, and the diffusion constant (K d) was 25 nl·(mg prot)−1·s−1. The apical transport of D-fructose was Na+-independent, phlorizin-, phloretin-, and cytochalasin B-insensitive, and did not show cis-inhibition by D-glucose or D-galactose. These properties, together with the detection of specific GLUT5 mRNA, indicate the presence of a low-affinity high-capacity GLUT5-type carrier in the chicken jejunum, responsible for the entry of D-fructose across the brush-border membrane of enterocytes. |
| Databáze: | OpenAIRE |
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