Glucose transporters in chromaffin cells: subcellular distribution and characterization.
The glucose transporter was identified and characterized by cytochalasin B binding in subcellular membrane fractions of chromaffin tissue. The binding was saturable with Kd of about 0.3 microM for each subcellular fraction. The Bmax capacity was 12-16 pmol/mg protein for enriched plasma membrane fractions, 6.3 pmol/mg protein for microsomal membrane preparations and 5.4 pmol/mg protein for chromaffin granule membranes. Irreversible photoaffinity labelling of the glucose-protectable binding sites with [3H]cytochalasin B followed by solubilization and polyacrylamide gel electrophoresis from enriched plasma membrane preparations demonstrated the presence of three molecular species: 97 +/- 10, 51.5 +/- 6 and 30 +/- 4 kDa. The chromaffin granule membranes showed only a molecular species of 80 +/- 10 kDa.
Delicado
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EG
Departamento de Bioquímica, Facultad de Veterinaria, Universidad Complutense de Madrid, Spain.
Torres
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Miras-Portugal
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MT
D000313:Adrenal Medulla / Q000378:metabolism / Q000648:ultrastructure; D000345:Affinity Labels / Q000378:metabolism; D000818:Animals; D002837:Chromaffin Granules / Q000378:metabolism*; D002838:Chromaffin System / Q000378:metabolism*; D003571:Cytochalasin B / Q000378:metabolism; D007700:Kinetics; D008970:Molecular Weight; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*; D010777:Photochemistry; D012995:Solubility; D013347:Subcellular Fractions / Q000201:enzymology / Q000378:metabolism*
D000345:Affinity Labels; D009004:Monosaccharide Transport Proteins; D003571:Cytochalasin B