Search results for "Models"
showing 10 items of 8211 documents
IKK-β inhibitors: An analysis of drug–receptor interaction by using Molecular Docking and Pharmacophore 3D-QSAR approaches
2010
Abstract The IKK kinases family represents a thrilling area of research because of its importance in regulating the activity of NF-kB transcription factors. The discovery of the central role played by IKK-β in the activation of transcription in response to apoptotic or inflammatory stimuli allowed to considerate its modulation as a promising tool for the treatment of chronic inflammation and cancer. To date, several IKK-β inhibitors have been discovered and tested. In this work, an analysis of the interactions between different classes of inhibitors and their biological target was performed, through the application of Molecular Docking and Pharmacophore/3D-QSAR approaches to a set of 141 in…
Latest advances in molecular topology applications for drug discovery
2015
Molecular topology (MT) has emerged in recent years as a powerful approach for the in silico generation of new drugs. In the last decade, its application has become more and more popular among the leading research groups in the field of quantitative structure-activity relationships (QSAR) and drug design. This has, in turn, contributed to the rapid development of new techniques and applications of MT in QSAR studies, as well as the introduction of new topological indices.This review collates the main innovative techniques in the field of MT and provides a description of the novel topological indices recently introduced, through an exhaustive recompilation of the most significant works carri…
Non-stochastic quadratic fingerprints and LDA-based QSAR models in hit and lead generation through virtual screening: theoretical and experimental as…
2005
In order to explore the ability of non-stochastic quadratic indices to encode chemical information in antimalarials, four quantitative models for the discrimination of compounds having this property were generated and statistically compared. Accuracies of 90.2% and 83.3% for the training and test sets, respectively, were observed for the best of all the models, which included non-stochastic quadratic fingerprints weighted with Pauling electronegativities. With a comparative purpose and as a second validation experiment, an exercise of virtual screening of 65 already-reported antimalarials was carried out. Finally, 17 new compounds were classified as either active/inactive ones and experimen…
On the contribution of molecular topology to drug design and discovery.
2010
Abstract The role of molecular topology (MT) in the design and selection of new drugs is discussed. After an overview of the different in silico molecular design current technologies, the QSAR analysis is dealt in detail with particular emphasis in the use of topological indices as molecular descriptors. The results of the application of MT in drug design and discovery are described and finally a possible explanation is given about some of the key reasons explaining it's the extraordinary performance.
Advances in the molecular modeling and quantitative structure–activity relationship-based design for antihistamines
2013
Nowadays the use of antihistamines (AH) is increasing steadily. These drugs are able to act on a variety of pathological conditions of the organism. A number of computer-aided (in silico) approaches have been developed to discover and develop novel AH drugs. Among these methods stand the ones based on drug-receptor docking, thermodynamics, as well as the quantitative structure-activity relationships (QSAR).This review collates the most recent advances in the use of computer approaches for the search and characterization of novel AH drugs. Within the QSAR methods, particular attention will be paid to those based on molecular topology (MT) because of their demonstrated efficacy in discovering…
Computational Methods in Developing Quantitative Structure-Activity Relationships (QSAR): A Review
2006
Virtual filtering and screening of combinatorial libraries have recently gained attention as methods complementing the high-throughput screening and combinatorial chemistry. These chemoinformatic techniques rely heavily on quantitative structure-activity relationship (QSAR) analysis, a field with established methodology and successful history. In this review, we discuss the computational methods for building QSAR models. We start with outlining their usefulness in high-throughput screening and identifying the general scheme of a QSAR model. Following, we focus on the methodologies in constructing three main components of QSAR model, namely the methods for describing the molecular structure …
Single-Molecule FRET Reveals a Cooperative Effect of Two Methyl Group Modifications in the Folding of Human Mitochondrial tRNALys
2011
Summary Using a combination of advanced RNA synthesis techniques and single molecule spectroscopy, the deconvolution of individual contributions of posttranscriptional modifications to the overall folding and stabilization of human mitochondrial tRNA Lys is described. An unexpected destabilizing effect of two pseudouridines on the native tRNA folding was evidenced. Furthermore, the presence of m 2 G10 alone does not facilitate the folding of tRNA Lys , but a stabilization of the biologically functional cloverleaf shape in conjunction with the principal stabilizing component m 1 A9 exceeds the contribution of m 1 A alone. This constitutes an unprecedented cooperative effect of two nucleotide…
RNA nucleotide methylation
2011
Methylation of RNA occurs at a variety of atoms, nucleotides, sequences and tertiary structures. Strongly related to other posttranscriptional modifications, methylation of different RNA species includes tRNA, rRNA, mRNA, tmRNA, snRNA, snoRNA, miRNA, and viral RNA. Different catalytic strategies are employed for RNA methylation by a variety of RNA-methyltransferases which fall into four superfamilies. This review outlines the different functions of methyl groups in RNA, including biophysical, biochemical and metabolic stabilization of RNA, quality control, resistance to antibiotics, mRNA reading frame maintenance, deciphering of normal and altered genetic code, selenocysteine incorporation,…
Molecular dynamics simulation of carboxy-myoglobin embedded in a trehalose-water matrix
2001
AbstractWe report on a molecular dynamics (MD) simulation of carboxy-myoglobin (MbCO) embedded in a water-trehalose system. The mean square fluctuations of protein atoms, calculated at different temperatures in the 100–300K range, are compared with those from a previous MD simulation on an H2O-solvated MbCO and with experimental data from Mössbauer spectroscopy and incoherent elastic neutron scattering on trehalose-coated MbCO. The results show that, for almost all the atomic classes, the amplitude of the nonharmonic motions stemming from the interconversion among the protein’s conformational substates is reduced with respect to the H2O-solvated system, and their onset is shifted toward hig…
Protein isotope effects in dihydrofolate reductase from Geobacillus stearothermophilus show entropic-enthalpic compensatory effects on the rate const…
2014
Catalysis by dihydrofolate reductase from the moderately thermophilic bacterium Geobacillus stearothermophilus (BsDHFR) was investigated by isotope substitution of the enzyme. The enzyme kinetic isotope effect for hydride transfer was close to unity at physiological temperatures but increased with decreasing temperatures to a value of 1.65 at 5 °C. This behavior is opposite to that observed for DHFR from Escherichia coli (EcDHFR), where the enzyme kinetic isotope effect increased slightly with increasing temperature. These experimental results were reproduced in the framework of variational transition-state theory that includes a dynamical recrossing coefficient that varies with the mass of…