Photoaffinity labelling of Ca 2+ channels with [ 3 H]azidopine
A 1,4‐dihydroypyridine arylazide photoaffinity ligand, [ 3 H]azidopine (50.6 Ci/mmol), has been synthesized. [ 3 H]Azidopine binds reversibly with a K d of 350 pM to guinea‐pig skeletal muscle membranes in the absence of ultraviolet light. The reversible [ 3 H]azidopine binding is inhibited stereose...
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| Published in | FEBS letters Vol. 169; no. 1; pp. 112 - 118 |
|---|---|
| Main Authors | , , , |
| Format | Journal Article |
| Language | English |
| Published |
09.04.1984
|
| Online Access | Get full text |
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| Summary: | A 1,4‐dihydroypyridine arylazide photoaffinity ligand, [
3
H]azidopine (50.6 Ci/mmol), has been synthesized. [
3
H]Azidopine binds reversibly with a
K
d
of 350 pM to guinea‐pig skeletal muscle membranes in the absence of ultraviolet light. The reversible [
3
H]azidopine binding is inhibited stereoselectively by 1,4‐dihydropyridines, phenylalkylamine Ca
2+
channel blockers and La
3+
. Covalent incorporation into membrane proteins after photolysis was investigated by sodium dodecyl sulfate polyacrylamide slab gel electrophoresis. [
3
H]Azidopine is photoincorporated specifically into a protein of
M
r
∼145 000. The covalent labelling of the
M
r
∼145 ooo band is inhibited stereoselectively by drugs and cations which block the reversible [
3
H]azidopine binding. It is suggested that [
3
H]azidopine is photoincorporated into a subunit of the putative Ca
2+
channel. |
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| ISSN: | 0014-5793 1873-3468 |
| DOI: | 10.1016/0014-5793(84)80299-9 |