Resveratrol induces autophagy by directly inhibiting mTOR through ATP competition

Resveratrol (RSV) is a natural polyphenol that has a beneficial effect on health, and resveratrol-induced autophagy has been suggested to be a key process in mediating many beneficial effects of resveratrol, such as reduction of inflammation and induction of cancer cell death. Although various resveratrol targets have been suggested, the molecule that mediates resveratrol-induced autophagy remains unknown. Here, we demonstrate that resveratrol induces autophagy by directly inhibiting the mTOR-ULK1 pathway. We found that inhibition of mTOR activity and presence of ULK1 are required for autophagy induction by resveratrol. In line with this mTOR dependency, we found that resveratrol suppresses the viability of MCF7 cells but not of SW620 cells, which are mTOR inhibitor sensitive and insensitive cancer cells, respectively. We also found that resveratrol-induced cancer cell suppression occurred ULK1 dependently. For the mechanism of action of resveratrol on mTOR inhibition, we demonstrate that resveratrol directly inhibits mTOR. We found that resveratrol inhibits mTOR by docking onto the ATP-binding pocket of mTOR (i.e., it competes with ATP). We propose mTOR as a novel direct target of resveratrol, and inhibition of mTOR is necessary for autophagy inductionopen

New solvation free energy function comprising intermolecular solvation and intramolecular self-solvation terms

Abstract Solvation free energy is a fundamental thermodynamic quantity that should be determined to estimate various physicochemical properties of a molecule and the desolvation cost for its binding to macromolecular receptors. Here, we propose a new solvation free energy function through the improvement of the solvent-contact model, and test its applicability in estimating the solvation free energies of organic molecules with varying sizes and shapes. This new solvation free energy function is constructed by combining the existing solute-solvent interaction term with the self-solvation term that reflects the effects of intramolecular interactions on solvation. Four kinds of atomic parameters should be determined in this solvation model: atomic fragmental volume, maximum atomic occupancy, atomic solvation, and atomic self-solvation parameters. All of these parameters for total 37 atom types are optimized by the operation of a standard genetic algorithm in such a way to minimize the difference between the experimental solvation free energies and those calculated by the solvation free energy function for 362 organic molecules. The solvation free energies estimated from the new solvation model compare well with the experimental results with the associated squared correlation coefficients of 0.88 and 0.85 for training and test sets, respectively. The present solvation model is thus expected to be useful for estimating the solvation free energies of organic molecules.</p

MOESM1 of Accuracy enhancement in the estimation of molecular hydration free energies by implementing the intramolecular hydrogen bond effects

Additional file 1. Contains chemical structures, experimental and calculated solvation free energies of 763 molecules used in this study

Two-Track Virtual Screening Approach to Identify the Dual Inhibitors of Wild Type and C481S Mutant of Bruton&apos;s Tyrosine Kinase

Bruton&apos;s tyrosine kinase (BTK) is responsible for the pathogenesis of various autoimmune diseases and chronic lymphocytic leukemia. However, the discovery of efficient medicines has seen limited success due to the constitutively active mutants that acquired the drug resistance. To disclose the dual inhibitors against the wild-type BTK and the problematic drug-resistant C481S mutant, a large chemical library was virtually screened with extensive molecular docking simulations using two target proteins. As a consequence of imposing the configurational restraint to make a hydrogen bond in the hinge region of BTK as well as modifying the ligand dehydration term in the scoring function, a total of 20 dual inhibitors were discovered with the range of the associated IC50 values from 2.5 to 15 mu M. All these dual inhibitors revealed the inhibitory activity against the C481S mutant to a comparable extent to that measured for the wild type. Among the new inhibitors, N-(3,5-dimethoxyphenyl)-6,7-dimethoxyquinazolin-4-amine (1) appeared to be most suitable as a starting point of the lead optimization due to the highest biochemical potency against the C481S mutant as well as the lowest molecular weight. To increase the potential of a drug candidate, 1 was modified into 6,7-dimethoxy-N-(pyridin-3-yl)quinazolin-4-amine (12) via chemical synthesis so as to possess better physicochemical properties without loss of the biochemical potency. 12 is suggested as a new effective molecular core from which numerous druggable dual inhibitors of the wild-type BTK and the C481S mutant would be derivatized.11Nsciescopu

Discovery of Picomolar ABL Kinase Inhibitors Equipotent for Wild Type and T315I Mutant via Structure-Based de Novo Design

Although the constitutively activated break-point cluster region-Abelson (ABL) tyrosine kinase is known to cause chronic myelogenous leukemia (CML), the prevalence of drug-resistant ABL mutants has made it difficult to develop effective anti-CML drugs. With the aim to identify new lead compounds for anti-CML drugs, we carried out a structure-based de novo design using the scoring function improved by implementing an accurate solvation free energy term. This approach led to the identification of ABL inhibitors equipotent for the wild type and the most drug-resistant T315I mutant of ABL at the picomolar level. Decomposition analysis of the binding free energy showed that a decrease in the desolvation cost for binding in the ATP-binding site could be as important as the strengthening of enzyme-inhibitor interaction to enhance the potency of an ABL inhibitor with structural modifications. A similar energetic feature was also observed in free energy perturbation (FEP) calculations. Consistent with the previous experimental and computational studies, the hydrogen bond interactions with the backbone groups of Met318 proved to be the most significant binding forces to stabilize the inhibitors in the ATP-binding sites of the wild type and T315I mutant. The results of molecular dynamics simulations indicated that the dyna122231sciescopu