High affinity binding of [ 125I]monoiodoapamin to isolated guinea-pig hepatocytes

The bee venom neurotoxin apamin has been labelled with 125I and its binding to isolated guinea-pig hepatocytes measured under physiological conditions. A single saturable component of [ 125I]monoiodoapamin binding with a K d of 350 pM and B max of 0.99 fmol/mg dry wt was identified. Native apamin di...

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Bibliographic Details
Published inFEBS letters Vol. 152; no. 2; pp. 265 - 269
Main Authors Cook, Nigel S., Haylett, Dennis G., Strong, Peter N.
Format Journal Article
LanguageEnglish
Published England Elsevier B.V 21.02.1983
Subjects
Animals
Apamin
Apamin - analogs & derivatives
Apamin - metabolism
Bee Venoms - metabolism
Ca-activated K-channel
Erythrocytes - metabolism
Guinea Pigs
Guinea-pig hepatocyte
In Vitro Techniques
Kinetics
Liver - metabolism
Male
Potassium - metabolism
Potassium Channels
Receptors, Cell Surface - metabolism
Guinea-pig hepatocyte
Apamin
Ca-activated K-channel
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Summary:The bee venom neurotoxin apamin has been labelled with 125I and its binding to isolated guinea-pig hepatocytes measured under physiological conditions. A single saturable component of [ 125I]monoiodoapamin binding with a K d of 350 pM and B max of 0.99 fmol/mg dry wt was identified. Native apamin displaced labelled apamin with a K d of 376 pM which is broadly in keeping with the concentrations found to inhibit K loss from guinea-pig hepatocytes. These observations, together with the binding found in other tissues, suggest that specific binding of labelled apamin is particularly associated with apamin-sensitive, Ca-activated K-channels.
ISSN:0014-5793
1873-3468
DOI:10.1016/0014-5793(83)80393-7