Figure 3
Off-target screen for CNO. (a) Radioligand assay determining the % inhibition of binding of the indicated test ligand to the stated target caused by 10 μM CNO. Results showing an inhibition >50% (crossing the orange vertical line) are considered to represent significant effects of CNO, and thereby highlight potential off-target effects (orange font). Note that 6 enzymes, COX1, COX2, PDE3A, PDE4O2, Lck kinase, and AChE, were probed in the same assay, but all resulted in an inhibition <20% (not shown). All values are the mean of 2 replicates of the assay. (b) Ki of CNO at the 8 significant off-target receptors identified in screen (a), as derived from concentration binding assays and calculated using the Cheng-Prusoff equation. Orange font indicates targets with a Ki < 100 nM. Values have been derived by non-linear regression of the competition curves generated with mean values of 2 replicates at 8 different concentrations of CNO (3*10−10–1*10−4 M) using Hill equation curve fitting. 4-DAMP, 1,1-dimethyl-4-diphenylacetoxypiperidinium iodide; 5-HT, serotonin; A2A, adenosine; AChE, acetylcholinesterase; AR, androgen receptor; AVP, arginine vasopressin; BTCP, 1-[1-(2-Benzo[b]thiopheneyl)cyclohexyl]piperidine hydrochloride; BZD, benzodiazepine; CB, cannabinoid receptor; CCK, cholecystokinin; CGS 19755, selfotel; CNO, clozapine-N-oxide; COX, cyclooxygenase; D, dopamine; DAMGO, [D-Ala2, N-MePhe4, Gly-ol]-enkephalin; DPDPE, [D-Pen2, D-Pen5]enkephalin; DOI, 2,5-Dimethoxy-4-iodoamphetamine; ETA, endothelin receptor; GR, glucocorticoid receptor; H, histamine; hERG, human ether-a-go-go-related gene; Ki, inhibition constant; KV, potassium channel; MAO-A, monoamine oxidase A; M, muscarinic; MDL 72222, bemesetron; NMDA, N-methyl-D-aspartate; NECA, N-Ethyl-5′-carboxamido adenosine; PDE, phosphodiesterase; SCH 23390, halobenzazepine; V1A, vasopressin receptor 1 A.
