In the present work, novel 7-aryl-10, 11-dihydro-7H-chromeno [4, 3-b]quinoline-6, 8(9H, 12H)-dione derivatives were synthesized by oxidation of 7-aryl-8, 9, 10, 12-tetrahydro-7H-chromeno[4, 3-b]quinoline-6, 8-diones in the presence of silica sulfuric acid/NaNO2 with yields of 64-74%. Cytotoxic activity of synthesized compounds was assessed on three different human cancer cell lines (K562, LS180...

Human immunodeficiency virus infection / acquired immunodeficiency syndrome (HIV/AIDS) is a disease pertained to the human immune system. Given its crucial role in viral replication, HIV-1 protease (HIV-1 PR) is a prime therapeutic target in AIDS therapy. In this regard, the dynamic aspects of ligand-enzyme interactions may indicate an important role of conformational variability in HIV-1 PR in...

In this research, we report the results of DFT calculations using xc-hybrid functional, B3LYP and employ NBO interpretation to investigate the stereoelectronic effects. Electrostatic and steric impacts on the conformational properties of 1,2-difluorodiazene (1), 1,2-dichlorodiazene (2) and 1,2-dibromodiazene (3) are also studied. Factors determining the thermodynamically stable molecular struct...

By the use of examples, mainly of rather rigid proteins, we hope to have shown that conformational analysis of proteins is a problem that is not simply related to the conformational analysis of small molecules. The primary difficulties with proteins are (1) the multitude of possible conformers, (2) the complex dynamical behaviour and (3) the degree of co-operativity within the molecules. Any ex...

Chromatin condensation to heterochromatin is a mechanism essential for widespread suppression of gene transcription, and the means by which a chromatin-associated protein, MENT, induces a terminally differentiated state in cells. MENT, a protease inhibitor of the serpin superfamily, is able to undergo conformational change in order to effect enzyme inhibition. Here, we sought to investigate whe...

In this study, we theoretically investigated Methyl hydrazinecarbodithioate by quantum chemical calculations for geometry optimization, vibration frequencies, and electronic structure parameters. The geometry optimization by DFT, ab initio MP2 method and the frequency calculation by DFT method was performed at the highest available Pople style 6-311G++(3df,3pd) basis set level. The semi-emp...

MOTIVATION It remains both a fundamental and practical challenge to understand and anticipate motions and conformational changes of proteins during their associations. Conventional normal mode analysis (NMA) based on anisotropic network model (ANM) addresses the challenge by generating normal modes reflecting intrinsic flexibility of proteins, which follows a conformational selection model for ...

In this perspective, we focus our discussion on how the single-molecule spectroscopy and statistical analysis are able to reveal enzyme hidden properties, taking the study of T4 lysozyme as an example. Protein conformational fluctuations and dynamics play a crucial role in biomolecular functions, such as in enzymatic reactions. Single-molecule spectroscopy is a powerful approach to analyze prot...

Many single-molecule experiments aim to characterize biomolecular processes in terms of kinetic models that specify the rates of transition between conformational states of the biomolecule. Estimation of these rates often requires analysis of a population of molecules, in which the conformational trajectory of each molecule is represented by a noisy, time-dependent signal trajectory. Although h...