Download or read book Protein Folding Simulations Combining Self Guided Langevin Dynamics and Temperature Based Replica Exchange written by and published by . This book was released on 2010 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computer simulations are increasingly being used to predict thermodynamic observables for folding small proteins. Key to continued progress in this area is the development of algorithms that accelerate conformational sampling. Temperature-based replica exchange (ReX) is a commonly used protocol whereby simulations at several temperatures are simultaneously performed and temperatures are exchanged between simulations via a Metropolis criterion. Another method, self-guided Langevin dynamics (SGLD), expedites conformational sampling by accelerating low-frequency large-scale motions through the addition of an ad hoc momentum memory term. In this work, we combined these two complementary techniques and compared the results against conventional ReX formulations of molecular dynamics (MD) and Langevin dynamics (LD) simulations for the prediction of thermodynamic folding observables of the Trp-cage mini-protein. All simulations were performed with CHARMM using the PARAM22+CMAP force field and the generalized Born molecular volume implicit solvent model. While SGLD-ReX does not fold up the protein significantly faster than the two conventional ReX approaches, there is some evidence that the method improves sampling convergence by reducing topological folding barriers between energetically similar nearnative states. Unlike MD-ReX and LD-ReX, SGLD-ReX predicts melting temperatures, heat capacity curves, and folding free energies that are closer in agreement to the experimental observations. However, this favorable result may be due to distortions of the relative free energies of the folded and unfolded conformational basins caused by the ad hoc force term in the SGLD model.

Download or read book Computational Approaches for Understanding Dynamical Systems Protein Folding and Assembly written by and published by Academic Press. This book was released on 2020-03-05 with total page 554 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational Approaches for Understanding Dynamical Systems: Protein Folding and Assembly, Volume 170 in the Progress in Molecular Biology and Translational Science series, provides the most topical, informative and exciting monographs available on a wide variety of research topics. The series includes in-depth knowledge on the molecular biological aspects of organismal physiology, with this release including chapters on Pairwise-Additive and Polarizable Atomistic Force Fields for Molecular Dynamics Simulations of Proteins, Scale-consistent approach to the derivation of coarse-grained force fields for simulating structure, dynamics, and thermodynamics of biopolymers, Enhanced sampling and free energy methods, and much more. Includes comprehensive coverage on molecular biology Presents ample use of tables, diagrams, schemata and color figures to enhance the reader's ability to rapidly grasp the information provided Contains contributions from renowned experts in the field

Download or read book Computational Methods to Study the Structure and Dynamics of Biomolecules and Biomolecular Processes written by Adam Liwo and published by Springer. This book was released on 2018-12-19 with total page 851 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive overview of modern computer-based techniques for analyzing the structure, properties and dynamics of biomolecules and biomolecular processes. It is organized in four main parts; the first one deals with methodology of molecular simulations; the second one with applications of molecular simulations; the third one introduces bioinformatics methods and the use of experimental information in molecular simulations; the last part reports on selected applications of molecular quantum mechanics. This second edition has been thoroughly revised and updated to include the latest progresses made in the respective field of research.

Download or read book Simulating Temperature Jumps for Protein Folding Studies written by Seonah Kim and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: Protein folding is described as a dynamic process of an ensemble of molecules reaching well-defined three dimensional structures to achieve biological activity from linear amino acids sequences. Many human diseases result from protein misfolding or aggregation. Enormous effort has been made both experimentally and theoretically for nearly 40 years to explain the basic principle and mechanism of protein folding and unfolding. Nonetheless, many of them are still unknown or incompletely understood, mainly due to the complexity of the systems and the fast folding time scale. Experimental and theoretical approaches are complementary with each other for the protein folding studies and hence, combination of the two is required to have better understanding. One of the most popular experimental methods for the protein folding studies is laser-induced temperature-jump (T-jump), because it has nanosecond resolution. In the first project, the T-jump on the polyalanine peptides (Ala20) was simulated as a proof-of-principle system to mimic the experimental measurements. Replica exchange molecular dynamics (REMD) were performed to obtain equilibrated ensembles as a proper conformational sampling, which was combined with multiplexed molecular dynamics to extract kinetic properties in line with experiments. In the second project, the same methodology used in the first project was applied to real proteins. Effect of frictional coefficient in the solvent model was approximated using Langevin dynamics. Computationall results on the two related 14-residue peptides were chosen and compared with experimental results. A ratio of relaxation time of the two peptides was determined by calculated Circular Dichroism (CD) spectra by a factor of ~1.2, while the experimental results were ~1.1.

Download or read book Issues in Specialized Chemical and Chemistry Topics 2011 Edition written by and published by ScholarlyEditions. This book was released on 2012-01-09 with total page 1316 pages. Available in PDF, EPUB and Kindle. Book excerpt: Issues in Specialized Chemical and Chemistry Topics: 2011 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Specialized Chemical and Chemistry Topics. The editors have built Issues in Specialized Chemical and Chemistry Topics: 2011 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Specialized Chemical and Chemistry Topics in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Issues in Specialized Chemical and Chemistry Topics: 2011 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.

Download or read book Computational Chemistry Methods in Structural Biology written by and published by Academic Press. This book was released on 2011-09-13 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published continuously since 1944, the Advances in Protein Chemistry and Structural Biology serial has been a continuous, essential resource for protein chemists. Covering reviews of methodology and research in all aspects of protein chemistry, including purification/expression, proteomics, modeling and structural determination and design, each volume brings forth new information about protocols and analysis of proteins while presenting the most recent findings from leading experts in a broad range of protein-related topics. This volume features articles on Computational Chemistry methods in Structural Biology. Essential resource for protein chemists This volume features articles on Computational Chemistry methods in Structural Biology

Download or read book Hybrid Biomolecular Modeling written by Slavica Jonic and published by Frontiers Media SA. This book was released on 2019-01-24 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: Models of biomolecular structure and dynamics are often obtained by combining simulation or prediction approaches (e.g., comparative modeling, Molecular Dynamics (MD) simulations, Normal Mode Analysis (NMA), etc.) with experimental approaches (e.g., Nuclear Magnetic Resonance (NMR), X-ray crystallography, Small-Angle X-ray Scattering (SAXS), Electron Microscopy (EM), etc.). Such hybrid modeling extends the capabilities of experimental techniques, by enriching structural information and facilitating dynamics studies of biomolecules. This eBook contains articles on methodological developments, applications, and challenges of hybrid biomolecular modeling that have been collected in the framework of the Frontiers Research Topic entitled “Hybrid Biomolecular Modeling”.

Download or read book Entropy and Free Energy in Structural Biology written by Hagai Meirovitch and published by CRC Press. This book was released on 2020-08-14 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nuclear Structure Physics connects to some of our fundamental questions about the creation of the universe and its basic constituents. At the same time, precise knowledge on the subject has led to the development of many important tools for humankind such as proton therapy and radioactive dating, among others. This book has chapters on some of the crucial and trending research topics in nuclear structure, including the nuclei lying on the extremes of spin, isospin and mass. A better theoretical understanding of these topics is important beyond the confines of the nuclear structure community. Additionally, the book will showcase the applicability and success of the different nuclear effective interaction parameters near the drip line, where hints for level reordering have already been seen, and where one can test the isospin-dependence of the interaction. The book offers comprehensive coverage of the most essential topics, including: • Nuclear Structure of Nuclei at or Near Drip-Lines • Synthesis challenges and properties of Superheavy nuclei • Nuclear Structure and Nuclear models - Ab-initio calculations, cluster models, Shell-model/DSM, RMF, Skyrme • Shell Closure, Magicity and other novel features of nuclei at extremes • Structure of Toroidal, Bubble Nuclei, halo and other exotic nuclei These topics are not only very interesting from a theoretical nuclear physics perspective but are also quite complimentary for ongoing nuclear physics experimental programs worldwide. The book chapters, written by experienced and well-known researchers/experts, will be helpful for master students, graduate students and researchers and serve as a standard and up-to-date research reference book on the topics covered.

Download or read book Simplified Models for Simulating Replica Exchange Simulations and Recovering Kinetics of Protein Folding written by Weihua Zheng and published by . This book was released on 2009 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: Protein folding is a fundamental problem in modern structural biology. The nature of the problem poses challenges to the understanding of the process via computer simulations. One of the challenges in the computer simulation of proteins at the atomic level is the efficiency of sampling conformational space. Replica exchange (RE) methods are widely employed to alleviate the difficulty. To study how to best employ RE to protein folding and binding problems, we constructed a kinetic network model for RE studies of protein folding and used this simplified model to carry out "simulations of simulations" to analyze how the underlying temperature dependence of the conformational kinetics and the basic parameters of RE all interact to affect the number of folding transitions observed. When protein folding follows anti-Arrhenius kinetics, we observe a speed limit for the number of folding transitions observed at the low temperature of interest, which depends on the maximum of the harmonic mean of the folding and unfolding transition rates at high temperature. The efficiency of temperature RE was also studied on a more complicated and realistic continuous two-dimensional potential. Comparison of the efficiencies obtained using the continuous and discrete models makes it possible to identify non-Markovian effects which slow down equilibration of the RE ensemble on the more complex continuous potential. In particular, the efficiency of RE is limited by the timescale of conformational relaxation within free energy basins. The other challenges we are facing in all-atom simulations is to obtain meaningful information on the slow kinetics and pathways of folding. We present a kinetic network model which recover the kinetics using RE-generated states as the nodes of a kinetic network. Choosing the appropriate neighbors and the microscopic rates between the neighbors, the correct kinetics of the system can be recovered by running a simulation on the network.

Download or read book Protein Folding Dynamics and Stability written by Prakash Saudagar and published by Springer Nature. This book was released on 2023-05-27 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes recent important advancements in protein folding dynamics and stability research, as well as explaining fundamentals and examining potential methodological approaches in protein science. In vitro, in silico, and in vivo method based research of how the stability and folding of proteins help regulate the cellular dynamics and impact cell function that are crucial in explaining various physiological and pathological processes. This book offers a comprehensive coverage on various techniques and related recent developments in the experimental and computational methods of protein folding, dynamics, and stability studies. The book is also structured in such a way as to summarize the latest developments in the fiddle and key concepts to ensure that readers can understand advanced concepts as well as the fundamental big picture. And most of all, fresh insights are provided into the convergence of protein science and technology. Protein Folding Dynamics and Stability is an ideal guide to the field that will be of value for all levels of researchers and advanced graduate students with training in biochemical laboratory research.

Download or read book Applications of Replica Exchange Method in All atom Protein Folding Simulations written by Thu Zar Wai Lwin and published by . This book was released on 2005 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Replica exchange Wang landau Simulations of Lattice Proteins for the Understanding of the Protein Folding Problem written by Guangjie Shi and published by . This book was released on 2016 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: Protein folding is studied within the context of two coarse-grained lattice models that separate all amino acids into only a few types. The hydrophobic-polar (HP) model is a simplified lattice protein model for simulating protein folding and for understanding many biological problems of interest. In this work, an "improved" model, the semi-flexible H0P model, was proposed by introducing a new type of "neutral" monomer, "0", i.e., neither hydrophobic nor polar and also taking into consideration the stiffness of bonds connecting monomers. Even though both models are highly simplified protein models, finding the lowest energy conformations and determining the density of states are extremely difficult. We applied replica-exchange Wang-Landau sampling with appropriate trial moves for determining the density of states of multiple HP and H0P proteins, from which the thermodynamic properties such as specific heat can be calculated. Moreover, we developed a heuristic method for determining the ground state degeneracy of lattice proteins, based on multicanonical sampling. It is applied during comprehensive studies of single-site mutations in specific lattice proteins with different sequences. The effects in which we are interested include structural changes in ground states, changes of ground state energy, degeneracy, and thermodynamic properties of the system. With respect to mutations, both extremely sensitive and insensitive positions in the protein sequence have been found. That is, ground state energies and degeneracies, as well as other thermodynamic and structural quantities may be either largely unaffected or may change significantly due to mutation. Moreover, comparison between the HP model and the semi-flexible H0P model have been performed based on two real proteins: Crambin and Ribonuclease A. We found that, compared with the HP model, the semi-flexible H0P model possesses significantly reduced ground state degeneracy, and rich folding signals as the proteins rearranging into native states from very compact structures at low temperatures. We calculated the free energy vs end-to-end distance as a function of temperature. The HP model shows a relatively shallow folding funnel and flat free energy minimum, reflecting the high degeneracy of the ground state. In contrast, the semi-flexible H0P model has a well developed, rough free energy funnel with a low degeneracy ground state. In both cases, folding funnels are asymmetric with temperature dependent shape.

Download or read book Computational Simulation of Biological Systems written by Wei Zhang and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Scientific understanding as well as the way of studying science has been greatly changed since the advent of computer modeling. Computer simulation has played a central role in bridging theoretical and experimental studies. In this work, computer simulations were applied to explore biological systems on both protein folding and protein structure prediction studies. In the first study, the folding mechanisms of two alanine based helical peptides (Fs-21 peptide and MABA bonded Fs-21 peptide) were investigated by all atom molecular dynamics simulations and compared with experimental results. Multi-phase folding processes were observed for both peptides. Temperature change affected the relative stability of different ensembles. Helix-turn-helix conformation was found to be the most populated state at 300K while the full helix became more stable at low temperature (273K). The turn structure was found to be stabilized mainly by hydrophobic interactions. In the second study, helix-coil transition theory was elaborately tested by both statistical and energetic methods based on simulations of alanine based peptides. A weighted Ising model was proposed, and the model-derived propagation constant agreed very well with the experimental results. Solvation effect and electrostatic interactions were found to be the two main contributors to helix-coil transition. The results challenged the classic helix-coil transition theory by proving that the single sequence assumption was not appropriate for helix-coil transition. Conformational sampling has been a long-standing issue in computational sciences. In the third study, we systematically tested the convergence of the Replica Exchange Molecular Dynamics method (REMD), which is a recently developed method for conformational sampling enhancement. The results suggested that REMD can significantly enhance the sampling efficiency and accurately reproduce the long-time MD results with high efficiency. However, fluctuations at low temperatures (300 K) indicated that REMD simulations did not converge within our simulation time (14 ns). Much longer REMD simulation time might be needed for the system to reach thermodynamic equilibrium than expected. Finding the optimal side chain packing is a common issue in structure prediction, protein design and protein docking. In the fourth study, a new method was presented. The method overcame the rough energy landscape problem and enabled all-atom MD simulation to be applied directly to protein structure refinement. The method showed very successful results on buried side-chain assignments, nearly 100% accuracy on all 6 randomly picked proteins was reached; the results also clearly demonstrated that the proposed method can significantly enhance conformational sampling. These encouraging results suggested prospective applications on many other protein related systems.

Download or read book Handbook of Materials Modeling written by Sidney Yip and published by Springer Science & Business Media. This book was released on 2007-11-17 with total page 2903 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first reference of its kind in the rapidly emerging field of computational approachs to materials research, this is a compendium of perspective-providing and topical articles written to inform students and non-specialists of the current status and capabilities of modelling and simulation. From the standpoint of methodology, the development follows a multiscale approach with emphasis on electronic-structure, atomistic, and mesoscale methods, as well as mathematical analysis and rate processes. Basic models are treated across traditional disciplines, not only in the discussion of methods but also in chapters on crystal defects, microstructure, fluids, polymers and soft matter. Written by authors who are actively participating in the current development, this collection of 150 articles has the breadth and depth to be a major contributor toward defining the field of computational materials. In addition, there are 40 commentaries by highly respected researchers, presenting various views that should interest the future generations of the community. Subject Editors: Martin Bazant, MIT; Bruce Boghosian, Tufts University; Richard Catlow, Royal Institution; Long-Qing Chen, Pennsylvania State University; William Curtin, Brown University; Tomas Diaz de la Rubia, Lawrence Livermore National Laboratory; Nicolas Hadjiconstantinou, MIT; Mark F. Horstemeyer, Mississippi State University; Efthimios Kaxiras, Harvard University; L. Mahadevan, Harvard University; Dimitrios Maroudas, University of Massachusetts; Nicola Marzari, MIT; Horia Metiu, University of California Santa Barbara; Gregory C. Rutledge, MIT; David J. Srolovitz, Princeton University; Bernhardt L. Trout, MIT; Dieter Wolf, Argonne National Laboratory.

Download or read book Self Assembled Peptide Nanostructures written by Jaime Castillo and published by CRC Press. This book was released on 2012-11-21 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: The self-organization of bionanostructures into well-defined functional machineries found in nature has been a priceless source of ideas for researchers. The molecules of life, proteins, DNA, RNA, etc., as well as the structures and forms that these molecules assume serve as rich sources of ideas for scientists or engineers who are interested in de

Download or read book Computer Simulations of Protein Folding and Aggregation written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Computer simulation is used to study the competition between protein folding and aggregation, especially the formation of ordered structures that are also known as amyloid fibrils. Employing simplified protein models, we simulate multi-protein systems at a greater level of detail than has previously been possible, probe the fundamental physics that govern protein folding and aggregation, and explore the energetic and structural characteristics of amorphous and fibrillar protein aggregates. We first tackle the aggregation problem by using a low-resolution model called the lattice HP model developed by Lau and Dill. Dynamic Monte Carlo simulations are conducted on a system of simple, two-dimensional lattice protein molecules. We investigate how changing the rate of chemical or thermal renaturation affects the folding and aggregation behavior of the model protein molecule by simulating three renaturation methods: infinitely slow cooling, slow but finite cooling, and quenching. We find that the infinitely slow cooling method provides the highest refolding yields. We then study how the variation of protein concentration affects the refolding yield by simulating the pulse renaturation method, in which denatured proteins are slowly added to the refolding simulation box in a stepwise manner. We observe that the pulse renaturation method provides refolding yields that are substantially higher than those observed in the other three methods even at high packing fractions. We then investigate the folding of a polyalanine peptide with the sequence Ac-KA14K-NH2 using a novel off-lattice, intermediate-resolution protein model originally developed by Smith and Hall. The thermodynamics of a system containing a single Ac-KA14K-NH2 molecule is explored by employing the replica exchange simulation method to map out the conformational transitions as a function of temperature. We also explore the influence of solvent type on the folding process by varying the relative strength of the sid.

Download or read book Metastability and Markov State Models in Molecular Dynamics written by Christof Schütte and published by American Mathematical Soc.. This book was released on 2013-12-26 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: Applications in modern biotechnology and molecular medicine often require simulation of biomolecular systems in atomic representation with immense length and timescales that are far beyond the capacity of computer power currently available. As a consequence, there is an increasing need for reduced models that describe the relevant dynamical properties while at the same time being less complex. In this book the authors exploit the existence of metastable sets for constructing such a reduced molecular dynamics model, the so-called Markov state model (MSM), with good approximation properties on the long timescales. With its many examples and illustrations, this book is addressed to graduate students, mathematicians, and practical computational scientists wanting an overview of the mathematical background for the ever-increasing research activity on how to construct MSMs for very different molecular systems ranging from peptides to proteins, from RNA to DNA, and via molecular sensors to molecular aggregation. This book bridges the gap between mathematical research on molecular dynamics and its practical use for realistic molecular systems by providing readers with tools for performing in-depth analysis of simulation and data-analysis methods. Titles in this series are co-published with the Courant Institute of Mathematical Sciences at New York University.