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- Gao, Chunxia, et al.
(författare)
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Analysis of Biphenyl-Type Inhibitors Targeting the Eg5 alpha 4/alpha 6 Allosteric Pocket
- 2017
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Ingår i: Acs Omega. - : American Chemical Society (ACS). - 2470-1343. ; 2:5, s. 1836-1849
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Tidskriftsartikel (refereegranskat)abstract
- Eg5 is a mitotic kinesin protein that plays an important role in the formation and maintenance of the bipolar spindle during the mitotic phase. Due to its potentially reduced side effects in cancer therapy, Eg5 is considered to be an attractive target for developing anticancer inhibitors. Herein, we report a computational modeling study involving biphenyl-type inhibitors known to interact with the a4/a6 allosteric pocket of Eg5. Compared to the well-known a2/L5/a3 allosteric inhibitors, biphenyltype inhibitors show a unique activity profile. In the Eg5-PVZB1194 (a biphenyl-type inhibitor) crystal structure, loop L11, which is located in the entrance of the alpha 4/alpha 6 allosteric-binding pocket, is missing due to crystal-packing effects. To better understand the role of this flexible loop upon biphenyl-type inhibitor-binding, MD simulations were performed to observe the L11 conformations from different states. It was demonstrated that L11 was more stabilized and showed less fluctuation when PVZB1194 was bound to Eg5. Residue Asn287 from L11 forms hydrogen bonding to the sulfone group of PVZB1194, whereby L11 moves inward to the alpha 4/alpha 6 allosteric pocket and moves away from the pocket in absence of the inhibitor. Pharmacophore, three-dimensional (3D)-QSAR, and ADME studies of biphenyl-type inhibitors of Eg5 were also performed. A best pharmacophore model, DDRRH. 6, was generated, having correlation coefficients in the 3D-QSAR study of R-2 = 0.81 and Q(2) = 0.64. Furthermore, docking studies were carried out to observe the interaction between the remaining biphenyl-type inhibitors with Eg5. In addition, on the basis of fragment docking, a structure-based pharmacophore was generated, which shares good overlap of the DHRR features of the pharmacophore model DDHRR. 6. The structure-based pharmacophore also contains extra hydrogen-bond acceptors and hydrophobic groups, features which provide possibilities in developing new or improved series of compounds.
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2. |
- Gao, Chunxia, et al.
(författare)
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Rational design and validation of a Tip60 histone acetyltransferase inhibitor
- 2014
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- Histone acetylation is required for many aspects of gene regulation, genome maintenance and metabolism and dysfunctional acetylation is implicated in numerous diseases, including cancer. Acetylation is regulated by histone acetyltransferases (HATs) and histone deacetylases and currently, few general HAT inhibitors have been described. We identified the HAT Tip60 as an excellent candidate for targeted drug development, as Tip60 is a key mediator of the DNA damage response and transcriptional co-activator. Our modeling of Tip60 indicated that the active binding pocket possesses opposite charges at each end, with the positive charges attributed to two specific side chains. We used structure based drug design to develop a novel Tip60 inhibitor, TH1834, to fit this specific pocket. We demonstrate that TH1834 significantly inhibits Tip60 activity in vitro and treating cells with TH1834 results in apoptosis and increased unrepaired DNA damage (following ionizing radiation treatment) in breast cancer but not control cell lines. Furthermore, TH1834 did not affect the activity of related HAT MOF, as indicated by H4K16Ac, demonstrating specificity. The modeling and validation of the small molecule inhibitor TH1834 represents a first step towards developing additional specific, targeted inhibitors of Tip60 that may lead to further improvements in the treatment of breast cancer.
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