Abstract
125I-[Tyr2]scyllatoxin allowed to label a single class of high-affinity receptors in membranes from the human neuroblastoma cell line NB-OK 1. The Kd of these receptors was 60 pM for scyllatoxin (Leiurotoxin I) and 20 pM for apamin and the Bmax was low (3.8 fmol/mg membrane protein). K+ increased toxin binding at low concentrations but exerted opposite effects at high concentrations. Ca2+, guanidinium and Na+ exerted only inhibitory effects on binding. Scyllatoxin binding sites were overexpressed 2.5-fold after a 24-h cell pretreatment with 2 mM butyrate. This effect was suppressed by cycloheximide.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Apamin / antagonists & inhibitors
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Apamin / metabolism
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Butyrates / pharmacology
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Butyric Acid
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Calcium / metabolism
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Cell Membrane / metabolism*
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Cycloheximide / pharmacology
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Gene Expression Regulation / drug effects*
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Guanidine
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Guanidines / metabolism
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Humans
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Kinetics
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Molecular Sequence Data
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Neuroblastoma
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Potassium / metabolism
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Potassium Channels*
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Radioligand Assay
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Receptors, Cholinergic / drug effects
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Receptors, Cholinergic / metabolism*
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Scorpion Venoms / metabolism*
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Sodium / metabolism
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Tumor Cells, Cultured
Substances
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Butyrates
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Guanidines
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Potassium Channels
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Receptors, Cholinergic
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Scorpion Venoms
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scyllatoxin receptor
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Butyric Acid
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leiurotoxin I
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Apamin
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Cycloheximide
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Sodium
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Guanidine
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Potassium
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Calcium