Detection of cannabinoid receptors by photoaffinity labelling.
S H Burstein, C A Audette, A Charalambous, S A Doyle, Y Guo, S A Hunter, A Makriyannis
Biochemical and Biophysical Research Communications April 15, 1991 DOI: 10.1016/0006-291x(91)90951-3 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Preclinical laboratory study Peer reviewed |
|---|---|
| Population | Mouse brain preparations and cultured S49 mouse lymphoma cells; mice for behavioral testing |
| Intervention | 2-iodo-5'-azido-delta 8-THC |
| Key points | The photoaffinity ligand 2-iodo-5'-azido-delta 8-THC bound with high affinity to cannabinoid sites in mouse brain (Kd = 5.60 pM) and S49 cells (Kd = 9.38 pM). Photolabelling revealed four brain ligand-protein adducts (85.5, 62.1, 30.0 and 25.5 kDa) that were diminished by 8 microM THC, and four adducts in S49 cells (62.1, 34.4, 16.9 and 13.5 kDa). The ligand produced a typical cannabinoid cataleptic response in mice, suggesting that one or more of these sites may mediate some actions of THC. |
Abstract
A novel [125I]-labelled photoaffinity ligand designed to detect cannabinoid binding sites has been used in mouse brain preparations and in cultured S49 mouse lymphoma cells. The ligand, 2-iodo-5'-azido-delta 8-THC, shows a high affinity for sites in both brain (Kd = 5.60 pM) and whole cell (Kd = 9.38 pM) systems. Photolabelling studies with brain samples revealed the existence of four ligand-protein adducts, of estimated molecular weights 85.5, 62.1, 30.0 and 25.5 kDa, that were diminished by prior exposure to 8 microM THC. A similar study with S49 cells gave adducts with apparent molecular weights of 62.1, 34.4, 16.9 and 13.5 kDa. The ligand produces a typical cannabinoid cataleptic response in mice suggesting that possibly one or more of the binding sites may be involved in some of the receptor mediated actions of THC.