Test Ligand | Emax ± S.E.M. | |
---|---|---|
Wild Type | I316T | |
nM | ||
Nonselective Alkaloids | ||
(±)-EKC | 185 ± 12 | 334 ± 485-160 |
Naltrexone | N.S. | N.S. |
Selective Alkaloids | ||
nBNI | N.S. | N.S. |
(−)-U-50,488 | 141 ± 12 | 259 ± 315-150 |
Peptides | ||
Dynorphin A 1–17 | 160 ± 11 | 163 ± 18 |
OFQ | N.S. | N.S. |
[35S]GTPγS binding was evaluated in duplicate at 6 to 10 ligand concentrations. Membranes prepared from transfected cells (ca. 10 μg) were incubated at room temperature for 60 min before harvesting by vacuum filtration. Nonspecific binding was defined by the addition of 20 μM GTPγS. EC50 values were determined from a minimum of three independent experiments using membranes prepared from independent transfections. Mutant I316T was compared to κ wild type using an unpaired Student's t test.