Identification of natural allosteric inhibitor for Akt1 protein through computational approaches and in vitro evaluation
| Autor: | T. Pragna Lakshmi, Ramadas Krishna, Amit Kumar, Veena Vijaykumar, Sakthivel Natarajan |
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| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Protein Conformation Allosteric regulation Drug Evaluation Preclinical AKT1 Quantitative Structure-Activity Relationship Apoptosis Molecular Dynamics Simulation Biochemistry Serine 03 medical and health sciences User-Computer Interface 0302 clinical medicine Allosteric Regulation Structural Biology Cell Line Tumor Humans Kinase activity Phosphorylation Protein kinase A Molecular Biology Protein kinase B Cell Proliferation Biological Products Chemistry Kinase General Medicine Cell Cycle Checkpoints 030104 developmental biology 030220 oncology & carcinogenesis Thermodynamics Pharmacophore Proto-Oncogene Proteins c-akt |
| Zdroj: | International journal of biological macromolecules. 96 |
| ISSN: | 1879-0003 |
| Popis: | Akt, a serine/threonine protein kinase, is often hyper activated in breast and prostate cancers, but with poor prognosis. Allosteric inhibitors regulate aberrant kinase activity by stabilizing the protein in inactive conformation. Several natural compounds have been reported as inhibitors for kinases. In this study, to identify potential natural allosteric inhibitor for Akt1, we generated a seven-point pharmacophore model and screened it through natural compound library. Quercetin-7-O-β-d-glucopyranoside or Q7G was found to be the best among selected molecules based on its hydrogen bond occupancy with key allosteric residues, persistent polar contacts and salt bridges that stabilize Akt1 in inactive conformation and minimum binding free energy during molecular dynamics simulation. Q7G induced dose-dependent inhibition of breast cancer cells (MDA MB-231) and arrested them in G1 and sub-G phase. This was associated with down-regulation of anti-apoptotic protein Bcl-2, up-regulation of cleaved caspase-3 and PARP. Expression of p-Akt (Ser473) was also down-regulated which might be due to Akt1 inhibition in inactive conformation. We further confirmed the Akt1 and Q7G interaction which was observed to have a dissociation constant (Kd) of 0.246μM. With these computational, biological and thermodynamic studies, we suggest Q7G as a lead molecule and propose for its further optimization. |
| Databáze: | OpenAIRE |
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