Cytotoxic effect and molecular docking of 4-ethoxycarbonylmethyl-1-(piperidin-4-ylcarbonyl)-thiosemicarbazide—a novel topoisomerase II inhibitor

The preliminary cytotoxic effect of 4-ethoxycarbonylmethyl-1-(piperidin-4-ylcarbonyl)-thiosemicarbazide hydrochloride (1)—a potent topoisomerase II inhibitor—was measured using a MTT assay. It was found that the compound decreased the number of viable cells in both estrogen receptor-positive MCF-7 and estrogen receptor-negative MDA-MB-231breast cancer cells, with IC(50) values of 146 ± 2 and 132 ± 2 μM, respectively. To clarify the molecular basis of the inhibitory action of 1, molecular docking studies were carried out. The results suggest that 1 targets the ATP binding pocket. [Figure: see text] ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00894-012-1679-6) contains supplementary material, which is available to authorized users

Physics-based visual characterization of molecular interaction forces

Molecular simulations are used in many areas of biotechnology, such as drug design and enzyme engineering. Despite the development of automatic computational protocols, analysis of molecular interactions is still a major aspect where human comprehension and intuition are key to accelerate, analyze, and propose modifications to the molecule of interest. Most visualization algorithms help the users by providing an accurate depiction of the spatial arrangement: the atoms involved in inter-molecular contacts. There are few tools that provide visual information on the forces governing molecular docking. However, these tools, commonly restricted to close interaction between atoms, do not consider whole simulation paths, long-range distances and, importantly, do not provide visual cues for a quick and intuitive comprehension of the energy functions (modeling intermolecular interactions) involved. In this paper, we propose visualizations designed to enable the characterization of interaction forces by taking into account several relevant variables such as molecule-ligand distance and the energy function, which is essential to understand binding affinities. We put emphasis on mapping molecular docking paths obtained from Molecular Dynamics or Monte Carlo simulations, and provide time-dependent visualizations for different energy components and particle resolutions: atoms, groups or residues. The presented visualizations have the potential to support domain experts in a more efficient drug or enzyme design process.Peer ReviewedPostprint (author's final draft

Identification of a high affinity binding site for abscisic acid on human lanthionine synthetase component C-like protein 2

Lanthionine synthetase component C-like protein 2 (LANCL2) has been identified as the mammalian receptor mediating the functional effects of the universal stress hormone abscisic acid (ABA) in mammals. ABA stimulates insulin independent glucose uptake in myocytes and adipocytes via LANCL2 binding in vitro, improves glucose tolerance in vivo and induces brown fat activity in vitro and in vivo. The emerging role of the ABA/LANCL2 system in glucose and lipid metabolism makes it an attractive target for pharmacological interventions in diabetes mellitus and the metabolic syndrome. The aim of this study was to investigate the presence of ABA binding site(s) on LANCL2 and identify the amino acid residues involved in ABA binding. Equilibrium binding assays ([3H]-ABA saturation binding and surface plasmon resonance analysis) suggested multiple ABA-binding sites, prompting us to perform a computational study that indicated one putative high-affinity and two low-affinity binding sites. Site-directed mutagenesis (single mutant R118I, triple mutants R118I/R22I/K362I and R118I/S41A/E46I) and equilibrium binding experiments on the mutated LANCL2 proteins identified a high-affinity ABA-binding site involving R118, with a KD of 2.6 nM ± 1.2 nM, as determined by surface plasmon resonance. Scatchard plot analysis of binding curves from both types of equilibrium binding assays revealed a Hill coefficient >1, suggesting cooperativity of ABA binding to LANCL2. Identification of the high-affinity ABA-binding site is expected to allow the design of ABA agonists/antagonists, which will help to understand the role of the ABA/LANCL2 system in human physiology and disease

ANTICANCER ACTIVITIES OF THIOSEMICARBAZIDES/THIOSEMICARBAZONES: A REVIEW

There have been tremendous development in the chemotherapy of cancer and researches are still developing new and more effective drugs to combat this disease. Thiosemicarbazides and thiosemicarbazone possess a wide range of biological applications. This key biological role is often related with their capability to inhibit the enzyme ribonucleotide reductase, similar to what is observed with potent anticancer drugs such as triapine and methisazone. Recent studies have revealed that thiosemicarbazones can inhibit topoisomerase II enzyme. This review discusses current advances of an emerging ‘new wave' of thiosemicarbazide/thiosemicarbazone and their metal complexes as potent anticancer agents, mode of action and toxicity caused by them

Structure-based design of pantothenate kinase inhibitors as lead structures for new antibiotics

BMED395MAMD-MEDB

Neurotensin(8–13) analogs as dual NTS1 and NTS2 receptor ligands with enhanced effects on a mouse model of Parkinson's disease

: The modulatory interactions between neurotensin (NT) and the dopaminergic neurotransmitter system in the brain suggest that NT may be associated with the progression of Parkinson's disease (PD). NT exerts its neurophysiological effects by interactions with the human NT receptors type 1 (hNTS1) and 2 (hNTS2). Therefore, both receptor subtypes are promising targets for the development of novel NT-based analogs for the treatment of PD. In this study, we used a virtually guided molecular modeling approach to predict the activity of NT(8-13) analogs by investigating the docking models of ligands designed for binding to the human NTS1 and NTS2 receptors. The importance of the residues at positions 8 and/or 9 for hNTS1 and hNTS2 receptor binding affinity was experimentally confirmed by radioligand binding assays. Further in vitro ADME profiling and in vivo studies revealed that, compared to the parent peptide NT(8-13), compound 10 exhibited improved stability and BBB permeability combined with a significant enhancement of the motor function and memory in a mouse model of PD. The herein reported NTS1/NTS2 dual-specific NT(8-13) analogs represent an attractive tool for the development of therapeutic strategies against PD and potentially other CNS disorders

Synthesis and biological evaluation of novel (thio)semicarbazone-based benzimidazoles as antiviral agents against human respiratory viruses

Respiratory RNA viruses are responsible for recurrent acute respiratory illnesses that stillrepresent a major medical need. Previously we developed a large variety of benzimidazole derivativesable to inhibit these viruses. Herein, two series of (thio)semicarbazone- and hydrazone-basedbenzimidazoles have been explored, by derivatizing 5-acetyl benzimidazoles previously reported by us,thereby evaluating the influence of the modification on the antiviral activity. Compounds6,8,16and17,bearing the 5-(thio)semicarbazone and 5-hydrazone functionalities in combination with the 2-benzylring on the benzimidazole core structure, acted as dual inhibitors of influenza A virus and humancoronavirus. For respiratory syncytial virus (RSV), activity is limited to the 5-thiosemicarbazone(25) and 5-hydrazone (22) compounds carrying the 2-[(benzotriazol-1/2-yl)methyl]benzimidazolescaffold. These molecules proved to be the most effective antiviral agents, able to reach the potencyprofile of the licensed drug ribavirin. The molecular docking analysis explained the SAR of thesecompounds around their binding mode to the target RSV F protein, revealing the key contacts forfurther assessment. The herein-investigated benzimidazole-based derivatives may represent valuablehit compounds, deserving subsequent structural improvements towards more efficient antiviralagents for the treatment of pathologies caused by these human respiratory viruses