Mitogen-activated protein kinase-activated protein kinase 2 (MK-2) has been identified as a drug target for the treatment of inflammatory diseases. in disease incidence and disease severity scores in the arthritic CIA (collagen induced arthritis) model, and this reduction was also observed for the MK-2 heterozygote mice . Moreover, MK-2 knockout mice are healthy and have a normal phenotype, while a genetic knockout of the p38 gene is embryonic lethal, suggesting an improved safety profile for MK-2 inhibition relative to p38 . All these evidences suggest that a selective MK-2 inhibitor may exhibit an efficacy equal to that of a p38 inhibitor but without affecting additional cellular pathways governed by p38 that may lead to undesirable adverse effects . Thus, inhibition of MK-2 provides a novel yet effective treatment for TNF–mediated diseases with little risk of side effects. Recently, several structural classes of compounds have been synthesized as MK-2 inhibitors, including the aminocyanopyridines , carboline analogs [10,13], tricyclic indole derivatives [8,14], benzothiophenes [15,16], thiourea analogs , spiro-3-piperidyl analogs , pyrrolopyridinone derivatives  and so on. Though these MK-2 inhibitors bear a certain amount of inhibitory activities, it is still difficult for these agents to obtain desirable characteristics to overcome inflammatory diseases. As such, developing the potential and selective MK-2 inhibitors is still a point of concern. modeling 193551-21-2 approaches [19C23], as a productive and cost-effective technology in the design of novel lead compounds, have been widely used in combination with experimental practices to facilitate the drug discovery process. Nevertheless, such computational studies on MK-2 inhibitors are still limited, with reports of only a single comparative molecular field analysis (CoMFA) research and pharmacophore modeling on pyrrolopyridine analogs [24,25], and a three-dimensional quantitative structural activity relationships (3D-QSAR) and docking modeling on carboline derivatives . Yang and co-workers found that 3-, 4-positions of the phenyl ring could introduce bulky substituents and electronegative groups, 193551-21-2 respectively, which leads to the increase in potency; and bulky and electropositive groups at the 3-position of the quinoline are not favorable in these pyrrolopyridine analogs . Investigations from Nayana model based on the pyrrolopyridine derivatives, reported by Kaushik and co-workers , identified the similar pharmacophoric features with that from Nayana: one hydrogen bond acceptor, two hydrogen bond donors, one hydrophobic group and one aromatic ring. But several questions remain unanswered: do other classes of MK-2 inhibitors also follow these rules? And if not, what are the possible rules for other molecules? To address this issue, in the present work, a more diverse set of thiourea derivatives, reported by Lin activity against the MK-2 enzyme, were used to perform the computational study. In addition, besides 3D-QSAR methods, molecular docking and molecular dynamics (MD) were also performed to investigate the possible interaction mode between the potential thiourea derivatives and MK-2. Thus, in the present work, a comprehensive computational method combining 3D-QSAR, molecular docking and MD technologies was used to investigate a series of thiourea inhibitors of MK-2 in order to build predictive models and probe the possible interaction mode between these ligands and the target. The reliability and robustness of the developed best models were estimated by the bootstrapping analysis, 10 fold cross-validation and value207.64157.509112.475106.868141.74764.605= 0.595, = 3, = 0.420, = 57.509 was obtained. Three field discriptors of S, E, Donor (D) present 0.250, 0.503 and 0.247, respectively. As can be seen from Table 1, the models from the alignments II and III cannot obtain statistically significant results in terms of internal and external predictive performances. Thus, our main analysis is restricted to the alignment I models for the prediction 193551-21-2 of MK-2 inhibitors. For the optimal CoMFA and CoMSIA models, besides the leave-one-out (LOO) validation, the cross-validation in groups using 10 folds repeating 10 times was also carried out, where the mean value of values of these 100 runs (namely, 1.15, where is the slope when the predicted values of the test set compounds (axis) are plotted against the observed values of compounds (axis) with the intercept set to zero; (5) the predicted pIC50 values of the training (black dot) and test (green diamond) sets for the two best 3D-QSAR models. Figure 3 gives 193551-21-2 the residual plots for optimal CoMFA and CoMSIA models. Clearly, good correlations are observed since the predicted values are almost as accurate as the Goat polyclonal to IgG (H+L)(HRPO) experimental activities for the whole dataset (especially for the.