Download or read book Ligand Receptor Energetics written by Irving M. Klotz and published by John Wiley & Sons. This book was released on 1997-03-14 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Energetische Wechselbeziehungen zwischen Ligand und Rezeptor sind besonders bei der Wechselwirkung kleiner Moleküle mit größeren unter Bildung komplexer Makromoleküle von Bedeutung, welche eine essentielle Rolle in Chemie, Biochemie, Biophysik, Pharmakologie und vielen anderen Gebieten spielen. Hier werden die thermodynamischen Ansätze experimentell und theoretisch erläutert - mit vielen Illustrationen zur Erklärung der Ligand-Bindungskonzepte.
Download or read book Introduction to Biomolecular Energetics written by Irving Klotz and published by Elsevier. This book was released on 2012-12-02 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduction to Biomolecular Energetics Including Ligand-Receptor Interactions focuses on the concepts of energetics and their biological applications, including the study of ligand-receptor interactions. The book provides quantitative calculations and addresses topics that have become more prominent in the biochemical and related sciences in recent years, including the first and second laws of thermodynamics, the concept of entropy, free energy or chemical potential, group-transfer potential, physicochemical behavior, and enzyme kinetics. This volume is organized into 10 chapters, and it begins with an overview of the scope of energetics and two general approaches to the field: the classical or phenomenological approach and the statistical-molecular approach. The chapters that follow explore the concepts of energy and entropy in the context of the first and second laws of thermodynamics, along with the relationships between work, heat, energy and entropy as an index of exhaustion. The discussion then shifts to the free energy function and general procedures for computing standard free energies. The book also introduces the reader to the fundamental relationship between chemical potential (free energy) and concentration; high-energy bond and the concept of group-transfer potential; the use of thermodynamic methods in the analysis of physicochemical behavior; and statistical thermodynamics. The final chapter examines the number of ligands that are bound by the receptor entity, how strongly the ligands are held, and the molecular nature of the forces of ligand-receptor interaction. This book will be of interest to biologists and those who want to understand the principles of energetics governing biochemical changes.
Download or read book Direct Measurement of the Energy Landscape of Ligand receptor Interactions written by Frank Heinz Schwemmer and published by . This book was released on 2010 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, a novel single molecule technique will be presented that will, for the first time, give direct access to the interaction energy landscapes of small molecules. The technique relies on the interpretation of thermal position fluctuations of a colloidal probe particle tethered to the molecular complex of interest and a geometrical amplification effect that converts Ångstrom scale fluctuations of the ligand in the binding pocket of the receptor to tens of nanometer fluctuation of the bead. The position of the bead is measured with 0.5 MHz bandwidth and 2 nm spatial resolution. The surface characteristic of the substrate was found to be critical for this new technique and various surface effects were observed. Methods were developed to block nonspecific interaction between the surfaces. The mobility of specifically bound particles was found to depend strongly on the density of specific bonds and the length of the molecular complex; low concentration and short linker lead to slow ligand-receptor mediated surface diffusion, high concentration and/or long linkers to an immobilization of the particle. Transient bond formation was observed for the intermediate range. Details of the interaction energy landscape were not resolved. However, a systematic change in the linker length from 22 Å to 29 Å led to a corresponding change in the lateral position fluctuations from 12.9 nm to 13.2 nm in excellent agreement with our theoretical calculations, confirming the geometrical amplification effect. Also, a new phenomenon of nanometer scale friction in the gap between the bead and the surface was discovered. In summary, the results underline that the novel technique might be able to measure details of the interaction energy landscape of a specific ligand-receptor bond and thus test theoretical predictions for its shape.
Download or read book Membrane Receptors Dynamics and Energetics written by Karel W. A. Wirtz and published by Springer. This book was released on 1987-08 with total page 510 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Protein Ligand Interactions written by Holger Gohlke and published by John Wiley & Sons. This book was released on 2012-06-04 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Innovative and forward-looking, this volume focuses on recent achievements in this rapidly progressing field and looks at future potential for development. The first part provides a basic understanding of the factors governing protein-ligand interactions, followed by a comparison of key experimental methods (calorimetry, surface plasmon resonance, NMR) used in generating interaction data. The second half of the book is devoted to insilico methods of modeling and predicting molecular recognition and binding, ranging from first principles-based to approximate ones. Here, as elsewhere in the book, emphasis is placed on novel approaches and recent improvements to established methods. The final part looks at unresolved challenges, and the strategies to address them. With the content relevant for all drug classes and therapeutic fields, this is an inspiring and often-consulted guide to the complexity of protein-ligand interaction modeling and analysis for both novices and experts.
Download or read book The Role of Conformational Energetics in Ligand Binding and Thermal Sensation written by Diana Koulechova and published by . This book was released on 2014 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: A major outstanding question in protein science is how different regions of a protein communicate with one another. Although we can identify action-at-a-distance phenomena when they occur, a generalized mechanism and an understanding sufficiently thorough as to allow for de novo design remain works in progress. This is particularly true for natively disordered proteins and channel proteins, both of which have traditionally been more technically difficult to characterize biophysically. In this work, I explore the functional relevance of their unique energetics and dynamics. The first project investigates the functional relevance of the hydrophobic core of disordered transcription factor MarA. We randomized the MarA hydrophobic core and selected for variants able to bind the consensus sequence. We find that MarA is highly intolerant of core mutation; this is in contrast to what is seen for the well-folded transcription factor [lambda]-repressor. Furthermore, core variants that do retain the ability to bind consensus sequence have differentially altered affinities for different binding partners. We propose that this can be explained by taking into account the varying energetic impact of these mutations on different MarA conformations and posit that residues distant from the active site can alter both binding affinity and specificity in natively disordered proteins. The second project aims to shed light on the mechanisms of thermosensation. Protein channel TRPA is a heat sensor in rattlesnakes but exhibits no heat-dependent activation in mammals. This discrepancy was mapped to select ankyrin repeats within the protein's cytoplasmic N-terminal domain. We hypothesized that temperature-dependent conformational changes within these repeats propagated to the pore region may be the thermosensing mechanism employed by TRPA1. The isolated repeats were purified and analyzed biophysically. Rattlesnake ankyrin repeats 3-8 are unique in that they do not appear to unfold with temperature on the timescale tested. The mechanism of this remarkable thermotolerance and its physiological relevance are currently under investigation.
Download or read book Free Energy Calculations written by Christophe Chipot and published by Springer Science & Business Media. This book was released on 2007-01-08 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: Free energy constitutes the most important thermodynamic quantity to understand how chemical species recognize each other, associate or react. Examples of problems in which knowledge of the underlying free energy behaviour is required, include conformational equilibria and molecular association, partitioning between immiscible liquids, receptor-drug interaction, protein-protein and protein-DNA association, and protein stability. This volume sets out to present a coherent and comprehensive account of the concepts that underlie different approaches devised for the determination of free energies. The reader will gain the necessary insight into the theoretical and computational foundations of the subject and will be presented with relevant applications from molecular-level modelling and simulations of chemical and biological systems. Both formally accurate and approximate methods are covered using both classical and quantum mechanical descriptions. A central theme of the book is that the wide variety of free energy calculation techniques available today can be understood as different implementations of a few basic principles. The book is aimed at a broad readership of graduate students and researchers having a background in chemistry, physics, engineering and physical biology.
Download or read book Simulation of Receptor ligand Recognition Mechanisms of Human Glutahione Transferases by Free Energy Landscape Calculation written by Paul Grassein and published by . This book was released on 2019 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: The hGSTs (Human Glutathione Transferases) proteins are enzymes which play a major role in the detoxification of our organism and which are involved in the development of cancer. The molecular mechanism by which the hGSTs select a wide variety of ligands (drugs, pesticides, etc.) is not understood to this day. Understanding the mechanisms of ligand-receptor recognition of hGSTs is an issue with a major societal and economic implication for the research on cancer and for the agro-food and pharmaceutical industries (see detailed project). In this thesis we will use high performance computing means to carry out simulations of molecular dynamics any atom in explicit hGSTs solver (system of several hundred thousand atoms). The team has extensive experience with this type of digital challenge acquired with the simulation of the HSP chaperone proteins. The approach of the free energy landscape analysis of developed HSPs recently in the team will be adapted to the study of GSTs and a new modeling of the free energy landscape (coupling of the Landau approach and of the molecular dynamics) will be developed in the thesis to elucidate the ligand-receptor mechanisms of GSTs. Odorous ligands derived from chemotherapy will be used as models and the theoretical results will be compared to experimental data obtained by different techniques (calorimetry, fluorescence, bio-layer interferometry, nanosondes) at the University of Burgundy.
Download or read book Binding Free Energy Calculations on Ligand receptor Complexes Applied to Malarial Protease Inhibitors written by Martin Nervall and published by . This book was released on 2007 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling Receptor Reorganization and Strain in Protein ligand Binding written by Kristina A. Paris and published by . This book was released on 2011 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: The key objectives of computational structure-based drug design include the prediction of the protein-ligand complex binding modes and estimation of the binding affinities. The overall affinity of a ligand for a receptor can be expressed as a balance between the strength of the interactions of a ligand to any particular binding-competent conformation of the receptor and the probability of occurrence of that conformation in the absence of the ligand. The receptor conformation probability distributions can be described by the free energy landscape of the receptor from which the strain free energy required to move from one conformation to another in the absence of a ligand may be estimated. The availability of large datasets of crystal structures in the PDB can provide information about the locations of free energy basins and their shapes. Here we utilize several methods in an effort to model the strain free energy of several receptors due to binding using the vast structural data publically available in the PDB. Clustering of 99 X-ray structures of HIV-1 reverse transcriptase at the flexible non-nucleoside inhibitor binding pocket elucidates eight discrete clusters, one of which displays a novel bound conformation of the functionally important primer grip. The clustering results served as a guide for replica exchange molecular dynamics simulations that offer a more in-depth look at the potential reorganization of the binding pocket. Clustering of 327 available X-ray structures of HIV-1 protease reveals less discrete variability in the substrate envelope than HIV-1 reverse transcriptase but does reveal some receptor reorganization that may be due to a combination of mutations. A linear response model for incorporation of receptor strain in modern protein-ligand binding affinity estimators is proposed. Receptor-receptor contact counts are employed as estimators for changes in receptor conformation due to binding of different ligands. Overall, the linear model produces apparent reduction in binding energy estimation errors and increases in the rank-order correlation with respect to initial values determined by the commercially available Glide 5.0 XP that does not take into account receptor reorganization. It also offers information as to the type of conformational changes, if any, that may contribute to the receptor reorganization energy. A null hypothesis test is constructed to evaluate the possibility of producing fits by chance alone. Finally, an alternative estimator approach using structurally significant intrareceptor distance descriptors, where there are less possible estimators, shows some promise for several drug targets. The model has the potential to allow for coarse-grained investigation of the conformational and energetic landscapes for binding inhibitors to flexible protein receptors.
Download or read book Modeling the Interaction and Energetics of Biological Molecules with a Polarizable Force Field written by Yue Shi and published by . This book was released on 2013 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accurate prediction of protein-ligand binding affinity is essential to computational drug discovery. Current approaches are limited by the accuracy of the underlying potential energy model that describes atomic interactions. A more rigorous physical model is critical for evaluating molecular interactions to chemical accuracy. The objective of this thesis research is to develop a polarizable force field with an accurate representation of electrostatic interactions, and apply this model to protein-ligand recognition and to ultimately solve practical problems in computer aided drug discovery. By calculating the hydration free energies of a series of organic small molecules, an optimal protocol is established to develop the electrostatic parameters from quantum mechanics calculations. Next, the systematical development and parameterization procedure of AMOEBA protein force field is presented. The derived force field has gone through extensive validations in both gas phase and condensed phase. The last part of the thesis involves the application of AMOEBA to study protein-ligand interactions. The binding free energies of benzamidine analogs to trypsin using molecular dynamics alchemical perturbation are calculated with encouraging accuracy. AMOEBA is also used to study the thermodynamic effect of constraining and hydrophobicity on binding energetics between phosphotyrosine(pY)-containing tripeptides and the SH2 domain of growth receptor binding protein 2 (Grb2). The underlying mechanism of an "entropic paradox" associated with ligand preorganization is explored.
Download or read book Understanding Virtual Solvent Through Large Scale Ligand Discovery written by Reed Stein and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Predicting new ligands and their binding poses for a protein target relies on an understanding of the physical forces that exist between the water-submerged protein and ligand. The relative favorability of these molecular and atomic interactions between the protein and ligand compared with their interactions with water determine the binding affinity, which in turn can be converted into a binding free energy. Protein-ligand binding energetics are, with varying levels of success, encoded into scoring functions, which at their best, can only partially emulate the true binding affinity of a protein-ligand binding event. In the context of virtually screening millions or hundreds of millions of drug-like ligands, molecular docking algorithms take advantage of scoring functions to rank the binding energies of these molecules relative to one another to help prioritize the most promising ligands.The focus of this dissertation is the balance between scoring function energy terms with an emphasis on water energetics, specifically the desolvation of the protein upon ligand binding. It is thought that our limited understanding of water is largely responsible for our limitations in discovering and designing drugs. This is due to the large number of roles that water can play, as well as its significant, and even dominant, contribution to protein-ligand binding energetics, which in the realm of molecular docking, is typically under-modeled or completely neglected. First, I focus on the incorporation of receptor desolvation into the standard DOCK3.7 scoring function to more accurately model protein-ligand binding interactions by including further contributions of water. This is the original implementation of Grid Inhomogeneous Solvation Theory applied to the model cavity, cytochrome c peroxidate, and spearheaded by Trent Balius and Marcus Fischer. Second, I discuss an extension of GIST in DOCK3.7, a new implementation that relies on pre-computed Gaussian-weighted GIST receptor desolvation enthalpies. This results in negligible slowdown of the standard DOCK3.7 scoring function, similar performance to the original implementation of GIST, and the identification of new ligands for the drug-like model system, AmpC Îø-lactamase. The work on receptor desolvation contained within these two chapters inspires the name of this thesis, and were started in my rotation and have continued until the end. Third, I focus on the use of property-matched and property-unmatched decoys for use in retrospective enrichment calculations prior to running a large-scale molecular docking virtual screen. Decoy molecules share the same physical properties as ligands that bind a protein but are topologically dissimilar to ensure that they do not actually bind the protein. What we found was that charge mismatching between ligands and decoys could bias one's docking setup towards artifactually strong performance. Chapter 3 focuses on how we both decreased and increased the property space of decoys relative to ligands to safeguard against these docking setup biases. Fourth, I employ this knowledge of protein-ligand binding affinities to identify novel selective melatonin receptor ligands that are active in in vivo circadian rhythm assays. Finally, I discuss my current project on the CB1 cannabinoid receptor in the context of analgesia, followed by future directions.
Download or read book Fitting Models to Biological Data Using Linear and Nonlinear Regression written by Harvey Motulsky and published by Oxford University Press. This book was released on 2004-05-27 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most biologists use nonlinear regression more than any other statistical technique, but there are very few places to learn about curve-fitting. This book, by the author of the very successful Intuitive Biostatistics, addresses this relatively focused need of an extraordinarily broad range of scientists.
Download or read book Molecular Theory of Solvation written by F. Hirata and published by Springer Science & Business Media. This book was released on 2006-04-11 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt: Molecular Theory of Solvation presents the recent progress in the statistical mechanics of molecular liquids applied to the most intriguing problems in chemistry today, including chemical reactions, conformational stability of biomolecules, ion hydration, and electrode-solution interface. The continuum model of "solvation" has played a dominant role in describing chemical processes in solution during the last century. This book discards and replaces it completely with molecular theory taking proper account of chemical specificity of solvent. The main machinery employed here is the reference-interaction-site-model (RISM) theory, which is combined with other tools in theoretical chemistry and physics: the ab initio and density functional theories in quantum chemistry, the generalized Langevin theory, and the molecular simulation techniques. This book will be of benefit to graduate students and industrial scientists who are struggling to find a better way of accounting and/or predicting "solvation" properties.
Download or read book Protein Ligand Interactions written by Mark A. Williams and published by Humana. This book was released on 2016-11-17 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proteins are the cell’s workers, their messengers and overseers. In these roles, proteins specifically bind small molecules, nucleic acid and other protein partners. Cellular systems are closely regulated and biologically significant changes in populations of particular protein complexes correspond to very small variations of their thermodynamics or kinetics of reaction. Interfering with the interactions of proteins is the dominant strategy in the development of new pharmaceuticals. Protein Ligand Interactions: Methods and Applications, Second Edition provides a complete introduction to common and emerging procedures for characterizing the interactions of individual proteins. From the initial discovery of natural substrates or potential drug leads, to the detailed quantitative understanding of the mechanism of interaction, all stages of the research process are covered with a focus on those techniques that are, or are anticipated to become, widely accessible and performable with mainstream commercial instrumentation. Written in the highly successful Methods in Molecular Biology series format, chapters contain introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and notes on troubleshooting and avoiding known pitfalls. Authoritative and accessible, Protein Ligand Interactions: Methods and Applications, Second Edition serves as an ideal guide for researchers new to the field of biophysical characterization of protein interactions – whether they are beginning graduate students or experts in allied areas of molecular cell biology, microbiology, pharmacology, medicinal chemistry or structural biology.
Download or read book Allosterism in Drug Discovery written by Dario Doller and published by Royal Society of Chemistry. This book was released on 2016-11-24 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although the concept of allosterism has been known for over half a century, its application in drug discovery has exploded in recent years. The emergence of novel technologies that enable molecular-level ligand-receptor interactions to be studied in studied in unprecedented detail has driven this trend. This book, written by the leaders in this young research area, describes the latest developments in allosterism for drug discovery. Bringing together research in a diverse range of scientific disciplines, Allosterism in Drug Discovery is a key reference for academics and industrialists interested in understanding allosteric interactions. The book provides an in-depth review of research using small molecules as chemical probes and drug candidates that interact allosterically with proteins of relevance to life sciences and human disease. Knowledge of these interactions can then be applied in the discovery of the novel therapeutics of the future. This book will be useful for people working in all disciplines associated with drug discovery in academia or industry, as well as postgraduate students who may be working in the design of allosteric modulators.
Download or read book Structural Bioinformatics Applications in Preclinical Drug Discovery Process written by C. Gopi Mohan and published by Springer. This book was released on 2019-01-10 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reviews the advances and challenges of structure-based drug design in the preclinical drug discovery process, addressing various diseases, including malaria, tuberculosis and cancer. Written by internationally recognized researchers, this edited book discusses how the application of the various in-silico techniques, such as molecular docking, virtual screening, pharmacophore modeling, molecular dynamics simulations, and residue interaction networks offers insights into pharmacologically active novel molecular entities. It presents a clear concept of the molecular mechanism of different drug targets and explores methods to help understand drug resistance. In addition, it includes chapters dedicated to natural-product- derived medicines, combinatorial drug discovery, the CryoEM technique for structure-based drug design and big data in drug discovery. The book offers an invaluable resource for graduate and postgraduate students, as well as for researchers in academic and industrial laboratories working in the areas of chemoinformatics, medicinal and pharmaceutical chemistry and pharmacoinformatics.
