Design, synthesis, biological evaluation and molecular dynamics of LAR inhibitors.

In this study, firstly, the pharmacophore model was established based on LAR inhibitors. ZINC database and drug-like database were screened by Hypo-1-LAR model, and the embryonic compound ZINC71414996 was obtained. Based on this compound, we designed 9 compounds. Secondly, the synthetic route of the compound was determined by consulting Reaxys and Scifinder databases, and 9 compounds (1a-1i) were synthesized by nucleophilic substitution, Suzuki reaction and so on. Meanwhile, their structures were confirmed by 1H NMR and 13C NMR. Thirdly, the Enzymatic assays was carried out, the biological evaluation of compounds 1a-1i led to the identification of a novel PTP-LAR inhibitor 1c, which displayed an IC50 value of 4.8 µM. At last, molecular dynamics simulation showed that compounds could interact strongly with the key amino acids LYS1350, LYS1352, ARG1354, TYR1355, LYS1433, ASP1435, TRP1488, ASP1490, VAL1493, SER1523, ARG1528, ARG1561, GLN1570, LYS1681, thereby inhibiting the protein activity. This study constructed the pharmacophore model of LAR protein, designed small-molecule inhibitors, conducted compound synthesis and enzyme activity screening, so as to provide a basis for searching for drug-capable lead compounds.

Synthesis, evaluation, molecular dynamics simulation and targets identification of novel pyrazole-containing imide derivatives.

A new series of novel pyrazole-containing imide derivatives were synthesized and evaluated for their anticancer activities against A-549, Bel7402, and HCT-8 cell lines. Among these compounds A2, A4, A11 and A14 possessed high inhibition activity against A-549 cell lines with IC50 values at 4.91, 3.22, 27.43 and 18.14 µM, respectively, better than that of 5-fluorouracil (IC50=59.27 µM). A2, A4, and A11 also exhibited significant inhibitory activity towards HCT-8 and Bel7402 cell lines. Interestingly, the Heat Shock Protein 90α (Hsp90α, PDB ID: 1UYK) was found to be the potential drug target of these synthesized compounds with the aid of PharmMapper server (http://lilab.ecust.edu.cn/pharmmapper/) and docking module of Schrödinger (Maestro 10.2). Additionally, molecular dynamics simulation was performed out to explore the most likely binding mode of compound A2 with Hsp90α.Communicated by Ramaswamy H. Sarma.

Identification of protein tyrosine phosphatase 1B (PTP1B) inhibitors through De Novo Evoluton, synthesis, biological evaluation and molecular dynamics simulation.

Protein tyrosine phosphatase 1B (PTP1B) is a widely expressed 50 kDa enzyme and the first intracellular PTP to be purified from human placental tissue. It has been proved that protein tyrosine phosphatase 1B played a significant role in the negative regulation of insulin signaling pathway and overexpression of PTP1B could lead to the decrease of insulin resistance. Therefore PTP1B has emerged as a novel promising therapeutic target for the treatment of type-2 diabetes mellitus. Computer aided drug design (CADD), chemical synthesis and biological activity assay resulted in the identification of a novel potent PTP1B inhibitor, compound 1a, which shared an IC50 value of 4.46 µM. Finally, the analysis of molecular dynamics simulation provided the theoretical basis for favorable activity of compound 1a.

Design, synthesis, biological evaluation and molecular dynamics simulation studies of (R)-5-methylthiazolidin-4-One derivatives as megakaryocyte protein tyrosine phosphatase 2 (PTP-MEG2) inhibitors for the treatment of type 2 diabetes.

PTP-MEG2 plays a significant role in insulin production and is able to enhance insulin signaling and improve insulin sensitivity. So, PTP-MEG2 inhibitors are closely associated with type 2 diabetes therapy. A series of novel (R)-5-methylthiazolidin-4-one derivatives were designed and synthesized, and their PTP-MEG2 inhibitory activities (IC50) were determined. Among the desired compounds, 1h shares the highest inhibitory activity (IC50 = 1.34 µM) against PTP-MEG2. Additionally, various post-dynamic analyses confirmed that when compound 1h bound to the PTP-MEG2, the protein conformations became unstable and the function of the pTyr recognition loop (Asn331-Cys338) would be disturbed. And thus, the ideal conformations needed for the catalytic activity was difficult to be maintained. In brief, these might be how the compound 1h worked. Furthermore, we also found that the key residues Arg332 would play a critical role in disturbing the residue interactions. AbbreviationsDCCMdynamic cross-correlation mappingDMFN,N-dimethylformamideDSSPdefinition of secondary structure of proteinsFOXOforkhead transcription factorsMDmolecular dynamicsPCAprincipal component analysisPDBprotein data bankPTKsprotein tyrosine kinasesPTPsprotein tyrosine phosphatasesPTP-MEG2megakaryocyte protein tyrosine phosphatase 2RINresidue interaction networkRINGResidue Interaction Network GeneratorRMSDroot means square deviationRMSFroot mean square fluctuationCommunicated by Ramaswamy H. Sarma.

Exploring the effect of aplidin on low molecular weight protein tyrosine phosphatase by molecular docking and molecular dynamic simulation study.

The low molecular weight protein tyrosine phosphatase (LMW-PTP) could regulate many signaling pathways, and it had drawn attention as a potential target for cancer. As previous report has indicated that the aplidin could inhibit the LMW-PTP, and thus, the relevant cancer caused by the abnormal regulation of the LMW-PTP could be remission. However, the molecular mechanism of inhibition of the LMW-PTP by the aplidin had not been fully understood. In this study, various computational approaches, namely molecular docking, MDs and post-dynamic analyses were utilized to explore the effect of the aplidin on the LMW-PTP. The results suggested that the intramolecular interactions of the residues in the two sides of the active site (Ser43-Ala55 and Pro121-Asn134) and the P-loop region (Leu13-Ser19) in the LMW-PTP was disturbed owing to the aplidin, meanwhile, the π-π interaction between Tyr131 and Tyr132 might be broken. The Asn15 might be the key residue to break the residues interactions. In a word, this study may provide more information for understanding the effect of inhibition of the aplidin on the LMW-PTP.

Exploring the effect of inhibitor AKB-9778 on VE-PTP by molecular docking and molecular dynamics simulation.

Diabetic macular edema, also known as diabetic eye disease, is mainly caused by the overexpression of vascular endothelial protein tyrosine phosphatase (VE-PTP) at hypoxia/ischemic. AKB-9778 is a known VE-PTP inhibitor that can effectively interact with the active site of VE-PTP to inhibit the activity of VE-PTP. However, the binding pattern of VE-PTP with AKB-9778 and the dynamic implications of AKB-9778 on VE-PTP system at the molecular level are poorly understood. Through molecular docking, it was found that the AKB-9778 was docked well in the binding pocket of VE-PTP by the interactions of hydrogen bond and Van der Waals. Furthermore, after molecular dynamic simulations on VE-PTP system and VE-PTP AKB-9778 system, a series of postdynamic analyses found that the flexibility and conformation of the active site undergone an obvious transition after VE-PTP binding with AKB-9778. Moreover, by constructing the RIN, it was found that the different interactions in the active site were the detailed reasons for the conformational differences between these two systems. Thus, the finding here might provide a deeper understanding of AKB-9778 as VE-PTP Inhibitor.

Exploring the reason for increased activity of SHP2 caused by D61Y mutation through molecular dynamics.

Juvenile myelomonocytic leukaemia, an aggressive myeloproliferative neoplasm, is characterized by thrombocytopenia, splenomegaly, fever and excess myelomonocytic cells. Approximately 35% of patients with JMML occur D61Y mutation in PTPN11, and it increases the activity of the protein. However, the effect of the D61Y mutation on SHP2 conformations in molecular basis is poorly understood. Therefore, the molecular dynamics simulations on SHP2-D61Y and SHP2-WT were performed to explore the effect of D61Y mutation on SHP2 and explain the reason for high activity of SHP2-D61Y mutant. The study on the RMSF, per-residue RMSD, PCA, DCCM and secondary structure found that the flexibilities of regions (residues His458-Ser460 and Gln506-Ala509) in SHP2-D61Y were higher than the corresponding regions in SHP2-WT, and the conformations of these regions almost transformed from α-helix and ß-strand to Turn, respectively. Thus, the catalytical sites in the PTP domain (residues Asn217-Thr524) were exposed to the substrate easily, which contributed to the enhancement of SHP2-D61Y activity. Moreover, the residue interaction network, H bond occupancy and binding free energy were calculated, revealing that conformational difference were caused by distinctions in residue-residue interactions between Asp/Tyr61-Gln506, Gln506-Gln510, Gln506-Phe251, Gln506-Gly60, Gln506-Tyr63, Asp/Tyr61-Cys459, Cys459-Ile463 and Cys459-Arg465. The study here may offer the valuable information to explore the reason for the increased activity of SHP2 after D61Y-mutation.

Exploring the effect of N308D mutation on protein tyrosine phosphatase-2 cause gain-of-function activity by a molecular dynamics study.

One of the most common protein tyrosine phosphatase-2 (SHP2) mutations in Noonan syndrome is the N308D mutation, and it increases the activity of the protein. However, the molecular basis of the activation of N308D mutation on SHP2 conformations is poorly understood. Here, molecular dynamic simulations were performed on SHP2 and SHP2-N308D to explore the effect of N308D mutation on SHP2 cause gain of function activity, respectively. The principal component analysis, dynamic cross-correlation map, secondary structure analysis, residue interaction networks, and solvent accessible surface area analysis suggested that the N308D mutation distorted the residues interactions network between the allosteric site (residue Gly244-Gly246) and C-SH2 domain, including the hydrogen bond formation and the binding energy. Meanwhile, the activity of catalytic site (residue Gly503-Val505) located in the Q-loop in mutant increased due to this region's high fluctuations. Therefore, the substrate had more chances to access to the catalytic activity site of the precision time protocol domain of SHP2-N308D, which was easy to be exposed. In addition, we had speculated that the Lys244 located in the allosteric site was the key residue which lead to the protein conformation changes. Consequently, overall calculations presented in this study ultimately provide a useful understanding of the increased activity of SHP2 caused by the N308D mutation.

Exploring the effect of E76K mutation on SHP2 cause gain-of-function activity by a molecular dynamics study.

Juvenile myelomonocytic leukemia (JMML), an invasive myeloproliferative neoplasm, is a childhood disease with very high clinical lethality. Somatic mutation E76K in SHP2 is the most commonly identified mutation found in up to 35% of patients with JMML. To investigate the effect of gain-of-function mutation-E76K on SHP2 activity, molecular dynamic simulations on the wild-type SHP2 (SHP2-WT) system and the mutated E76K (SHP2-E76K) system were performed. The evaluation of stability of these two systems indicated that the simulated trajectories were stable after simulation for 3 nanoseconds. The root mean square fluctuation and the per-residue root mean square deviation illustrated that there were two regions (residues Tyr 81-Glu 83 and Glu 258-Leu 261) in the wild-type system and the mutated system, which had large differences. The principal component analysis, dynamic cross correlation maps analysis, as well as secondary structure analysis suggested that the mutated E76K impacted the movement of these two regions in SHP2 protein. Furthermore, residue interaction network analysis, hydrogen bond occupancy, and binding free energies analysis were used to explain how the two regions were specifically affected by the mutant. The results indicated that the primary variances between SHP2-WT and SHP2-E76K were the different interactions between Glu/Lys 76 and Arg 265, Tyr 80 and Leu 77, Leu 77 and Tyr 81, Thr 73 and Glu 258, Ala 75 and Cys 259, Phe 71 and Tyr 81, Ala 75 and Glu 258, and Tyr 73 and Glu/Lys 76. Consequently, these findings here might provide insights into the increased activity in SHP2-E76K.