Binding of hypoglycaemic sulphonylureas to an artificial phospholipid bilayer

Deleers, Michel; Malaisse, Willy

doi:10.1007/bf00252264

Cited by 22 publications

(6 citation statements)

References 25 publications

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“…It is, nevertheless, a reassuring finding that 3H-glibenclamide is internalized to a rather large extent. We have already indicated [3] that the uptake of glibenclamide (0.1 mmol/1) by intact islets would correspond to a sulfonylurea/phospholipid molar ratio close to unity if the hypoglycaemic sulfonylurea were to be located solely in the plasma membrane.…”

Section: Discussionmentioning

confidence: 99%

“…The existence of specific membrane receptors for sulfonylureas was even postulated [2]. However, the criteria adopted for specific binding are also fulfilled when sulfonylureas interact with phospholipid bilayers in an artificial system [3]. The present ultrastructural study was undertaken to verify whether 3H-glibenclamide is indeed solely bound to the plasma membrane of islet cells without being internalized into such cells.…”

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confidence: 93%

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Internalization of 3H-glibenclamide in pancreatic islet cells

et al. 1986

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Diabetologia © Springer-Veflag 1986 Summary. As judged by autoradiographic criteria at the optical level, rat islet cells progressively accumulate 3H-glibenclamide over 1 to 30 min incubation at 24 °C. The labeled material associates with all endocrine cells, but is preferentially seen within B cells. The total uptake of 3H-glibenclamide (1.0 Ixmol/1) is little affected by the presence of unlabeled glibenclamide (0.2 mmol/1), but is significantly decreased at 4 °C (p < 0.05). At the electron microscopic level, less than 15% of the autoradiographic grains are located at the B cell plasma membrane and 72-79% of the grains found over the cytoplasm are associated with insulin secretory granules. Such a pattern is observed both after short (1 min) or prolonged (30 min) incubation, and at 4 or 24 °C. It is proposed that the insulinotropic action of glibenclamide is not necessarily attributable to primary events located solely at the cell surface.

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Section: Discussionmentioning

confidence: 99%

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confidence: 93%

Internalization of 3H-glibenclamide in pancreatic islet cells

et al. 1986

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“…This might be due to selective denaturation of binding proteins with low affinity during solubilization in the presence of Triton X-100. Alternatively, it is conceivable that low affinity binding reflects binding of glibenclamide to phospholipids in the microsomal membranes (Deleers & Malaisse, 1984). After solubilization these phospholipids probably escape precipitation by polyethylene glycol.…”

Section: Discussionmentioning

confidence: 99%

Effect of MgATP on pinacidil‐induced displacement of glibenclamide from the sulphonylurea receptor in a pancreatic β‐cell line and rat cerebral cortex

Schwanstecher

Brandt

Behrends

et al. 1992

British J Pharmacology

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“…2 and 3A;Schwanstecher et al ., 1992a,b) . This might reflect binding to phospholipids in the microsomal membranes (Deleers and Malaisse, 1984), which probably escape precipitation by polyethylene glycol . However, low-affinity binding sites were detected for binding of 1125I]N3-GA to solubilized sites when using IN3 -GA as displacing drug (Fig .…”

Section: Photoaffinity Labeling With ['Z I]n 3 -Gamentioning

confidence: 99%

Photoaffinity Labeling of the Cerebral Sulfonylurea Receptor Using a Novel Radioiodinated Azidoglibenclamide Analogue

Schwanstecher

Löser

Chudziak

et al. 1994

Journal of Neurochemistry

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In previous studies evidence has been presented by photoaffinity labeling that a polypeptide of 145–150 kDa represents the cerebral sulfonylurea receptor. However, covalent incorporation of [3H]glibenclamide or a 125I‐labeled glibenclamide analogue into the sulfonylurea receptor required high amounts of photoenergy and took place with low yield of photoinsertion. To provide a probe with increased photoreactivity a 4‐azido‐5‐iodosalicyloyl analogue of glibenclamide was synthesized. Binding experiments revealed specific and reversible high‐affinity binding of this novel probe to the particulate (KD = 0.13 nM) and solubilized (KD = 0.56 nM) sulfonylurea receptor from cerebral cortex. The novel probe showed >100‐fold higher sensitivity to irradiation at 356 nm than glibenclamide. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis revealed specific photoincorporation into a cerebral protein of 175 kDa and indicated an efficiency of photoincorporation of 9%. From dissociation binding curves following irradiation photoincorporation was estimated as 28% of specifically bound ligand. Photoincorporation into the 175‐kDa protein following saturation binding of the novel probe to particulate sites from cerebral cortex indicated a KD value of 0.38 nM. Inhibition of photoincorporation into this protein by glibenclamide, glipizide, and tolbutamide revealed KD values for these sulfonylureas of 0.06 nM, 1.6 nM, and 1.2 µM, respectively. These results show that the novel photoaffinity ligand can be used as a probe for detection and characterization of the sulfonylurea receptor and suggest that a 175‐kDa protein represents the cerebral sulfonylurea receptor.

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Binding of hypoglycaemic sulphonylureas to an artificial phospholipid bilayer

Cited by 22 publications

References 25 publications

Internalization of 3H-glibenclamide in pancreatic islet cells

Internalization of 3H-glibenclamide in pancreatic islet cells

Effect of MgATP on pinacidil‐induced displacement of glibenclamide from the sulphonylurea receptor in a pancreatic β‐cell line and rat cerebral cortex

Photoaffinity Labeling of the Cerebral Sulfonylurea Receptor Using a Novel Radioiodinated Azidoglibenclamide Analogue

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