An explanation corresponding to each descriptor is provided in Table 2. Virtual Screening By using the above mentioned models, we have been able to filter the ChemDiv database, selleckchem Wortmannin that has approxi mately 0. 7 million compounds. We have used a Hypogen pharmacophore model as a primary filter. The database search retrieved 15,110 hits and the top scoring 5,000 compounds with reasonable fit values, which are in the range 7. 61 9. 17 have been considered for further filtering. Following the pharmacophore search, the RP classification model has been applied to 5000 com pounds, of which 1806 compounds are classified as IKKb inhibitors. In the VS cascade, the final filter is molecular docking. All 1,806 compounds are subjected to heavy and light constrained docking and as a result, 6 and 358 hit compounds were reported, respectively.

Finally, the top scoring 31 com pounds from both docking methods have been selected. Of these, only 29 compounds available from suppliers were subjected to in vitro screening. Hit analysis The IKKb enzyme inhibition screening of 29 compounds revealed that two compounds have an inhibition effect of more than 20% at 10uM concentration. The first compound, with 42. 5% of inhibition, was found to have an IC50 value at 20. 3 uM. The positive control, Bayer 5a has been measured to have an IC50 value of 0. 17 uM, which is 6. 96 fold higher than that reported by Murata et al. and could be due to differences in assay conditions. Based on the Bayer 5a screening result, it is expected that the hit compounds will be more potent in recombinant human IKKb inhibition assays.

The hit molecule VH01 is based on a pyran moiety that makes five Hbond interactions at the ATP binding pocket, two Hbonds with the hinge region Cys99, and establishes three other bonds between various functional groups of lead mole cules and residues such as Lys44, Gly168 and Asn150. The molecule can be stabilized well in the pocket and therefore, has a high docking score of 22. 60. Carfilzomib The reported hit molecule is specifically derived from a light constraint method, because heavy con straints force the conformation of any molecule to inter act with the hinge region. Therefore, the docking score falls as these compounds can now make ideal interac tions with the hinge region, however, they fail to inhibit IKKb in real time. Hence, we have proposed the light constraint approach, that can be applied to locate mole cules in the deep buried binding pocket as the heavy constraint method can only produce unrealistic hits. Moreover, our previously reported screening also sup ports the light constraint method. The VH02 compound has a low inhibition effect of 20. 6% at 10 uM concentration, due to which it was not considered further for IC50 calculation.