125I-Labelled mapacalcine: a specific tool for a pharmacological approach to a receptor associated with a new calcium channel on mouse intestinal membranes.
Biochem J
; 331 ( Pt 1): 177-84, 1998 Apr 01.
Article
in En
| MEDLINE
| ID: mdl-9512477
ABSTRACT
Mapacalcine is a small protein (Mr=19041) composed of two homologous chains purified from the marine sponge Cliona vastifica. Recently, we demonstrated that it was able to specifically block a Ca2+ channel which could not be related to already described channels on mouse intestinal myocytes. This Ca2+ current was insensitive to the known peptidic and organic calcium channel blockers. Mapacalcine was ineffective on T-type and L-type Ca2+ currents present on rat portal vein myocytes [Morel, Drobecq, Sautière, Tartar, Mironneau, Qar, Lavie, and Hugues (1997) Mol. Pharmacol. 51, 1042-1052]. We report here the preparation and purification of a monoiodo-derivative of mapa-calcine which retains its biological properties. Binding parameters of mapacalcine to its receptors have been characterized on mouse intestinal membranes. It binds to its receptors with a Kd=0. 8 nM, and a maximal binding capacity of 171 fmol/mg of protein on membrane preparations. Our data show that we have prepared a tool that is usable for pharmacological studies of a receptor associated with a new type of calcium channel for which no ligand was available until now.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Calcium Channel Blockers
/
Calcium Channels
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Proteins
/
Cell Membrane
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Receptors, Cell Surface
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Intestinal Mucosa
Type of study:
Risk_factors_studies
Limits:
Animals
Language:
En
Journal:
Biochem J
Year:
1998
Document type:
Article
Affiliation country:
Francia