scholarly journals Trajectory-Based Parameterization of a Coarse-Grained Forcefield for High-Thoughput Protein Simulation

2017 ◽  
Author(s):  
John M. Jumper ◽  
Karl F. Freed ◽  
Tobin R. Sosnick
Keyword(s):  
Computational Efficiency ◽  
De Novo ◽  
Coarse Grained ◽  
Side Chains ◽  
Time Step ◽  
Trade Off ◽  
Protein Simulation ◽  
Starting Point ◽  
Folding Dynamics ◽  
Contrastive Divergence

The traditional trade-off in biomolecular simulation between accuracy and computational efficiency is predicated on the assumption that detailed forcefields are typically well-parameterized (i.e. obtaining a significant fraction of possible accuracy). We re-examine this trade-off in the more realistic regime in which parameterization is a greater source of bias than the level of detail in the forcefield. To address parameterization of coarse-grained forcefields, we use the contrastive divergence technique from machine learning to train directly from simulation trajectories on 450 proteins. In our scheme, the computational efficiency of the model enables high accuracy through precise tuning of the Boltzmann ensemble over a large collection of proteins. This method is applied to our recently developed Upside model [1], where the free energy for side chains are rapidly calculated at every time-step, allowing for a smooth energy landscape without steric rattling of the side chains. After our contrastive divergence training, the model is able to fold proteins up to approximately 100 residues de novo on a single core in CPU core-days. Additionally, the improved Upside model is a strong starting point both for investigation of folding dynamics and as an inexpensive Bayesian prior for protein physics that can be integrated with additional experimental or bioinformatic data.

scholarly journals Discovery and Optimization of Selective Inhibitors of Meprin α (Part I)

2021 ◽  
Vol 14 (3) ◽  
pp. 203 ◽  
Author(s):  
Shurong Hou ◽  
Juan Diez ◽  
Chao Wang ◽  
Christoph Becker-Pauly ◽  
Gregg B. Fields ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
De Novo ◽  
Selective Inhibitors ◽  
Preclinical Development ◽  
Starting Point ◽  
Good Starting Point ◽  
Parallel Screening ◽  
Low Cytotoxicity

Meprin α and β are zinc-dependent proteinases implicated in multiple diseases including cancers, fibrosis, and Alzheimer’s. However, until recently, only a few inhibitors of either meprin were reported and no inhibitors are in preclinical development. Moreover, inhibitors of other metzincins developed in previous years are not effective in inhibiting meprins suggesting the need for de novo discovery effort. To address the paucity of tractable meprin inhibitors we developed ultrahigh-throughput assays and conducted parallel screening of >650,000 compounds against each meprin. As a result of this effort, we identified five selective meprin α hits belonging to three different chemotypes (triazole-hydroxyacetamides, sulfonamide-hydroxypropanamides, and phenoxy-hydroxyacetamides). These hits demonstrated a nanomolar to micromolar inhibitory activity against meprin α with low cytotoxicity and >30-fold selectivity against meprin β and other related metzincincs. These selective inhibitors of meprin α provide a good starting point for further optimization.

scholarly journals Identification of 3,4-Dihydro-2H,6H-pyrimido[1,2-c][1,3]benzothiazin-6-imine Derivatives as Novel Selective Inhibitors of Plasmodium falciparum Dihydroorotate Dehydrogenase

2021 ◽  
Vol 22 (13) ◽  
pp. 7236
Author(s):  
Endah Dwi Hartuti ◽  
Takaya Sakura ◽  
Mohammed S. O. Tagod ◽  
Eri Yoshida ◽  
Xinying Wang ◽  
...  
Keyword(s):  
Drug Target ◽  
De Novo ◽  
Dihydroorotate Dehydrogenase ◽  
Chemical Library ◽  
New Class ◽  
De Novo Biosynthesis ◽  
Starting Point ◽  
Novel Drugs ◽  
Low Toxicity ◽  
Fourth Step

Plasmodium falciparum’s resistance to available antimalarial drugs highlights the need for the development of novel drugs. Pyrimidine de novo biosynthesis is a validated drug target for the prevention and treatment of malaria infection. P. falciparum dihydroorotate dehydrogenase (PfDHODH) catalyzes the oxidation of dihydroorotate to orotate and utilize ubiquinone as an electron acceptor in the fourth step of pyrimidine de novo biosynthesis. PfDHODH is targeted by the inhibitor DSM265, which binds to a hydrophobic pocket located at the N-terminus where ubiquinone binds, which is known to be structurally divergent from the mammalian orthologue. In this study, we screened 40,400 compounds from the Kyoto University chemical library against recombinant PfDHODH. These studies led to the identification of 3,4-dihydro-2H,6H-pyrimido[1,2-c][1,3]benzothiazin-6-imine and its derivatives as a new class of PfDHODH inhibitor. Moreover, the hit compounds identified in this study are selective for PfDHODH without inhibition of the human enzymes. Finally, this new scaffold of PfDHODH inhibitors showed growth inhibition activity against P. falciparum 3D7 with low toxicity to three human cell lines, providing a new starting point for antimalarial drug development.

scholarly journals Computational Analysis of African Swine Fever Virus Protein Space for the Design of an Epitope-Based Vaccine Ensemble

Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1078 ◽  
Author(s):  
Albert Ros-Lucas ◽  
Florencia Correa-Fiz ◽  
Laia Bosch-Camós ◽  
Fernando Rodriguez ◽  
Julio Alonso-Padilla
Keyword(s):  
T Cell ◽  
Vaccine Development ◽  
De Novo ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Economic Losses ◽  
Virus Protein ◽  
Hemorrhagic Disease ◽  
Starting Point

African swine fever virus is the etiological agent of African swine fever, a transmissible severe hemorrhagic disease that affects pigs, causing massive economic losses. There is neither a treatment nor a vaccine available, and the only method to control its spread is by extensive culling of pigs. So far, classical vaccine development approaches have not yielded sufficiently good results in terms of concomitant safety and efficacy. Nowadays, thanks to advances in genomic and proteomic techniques, a reverse vaccinology strategy can be explored to design alternative vaccine formulations. In this study, ASFV protein sequences were analyzed using an in-house pipeline based on publicly available immunoinformatic tools to identify epitopes of interest for a prospective vaccine ensemble. These included experimentally validated sequences from the Immune Epitope Database, as well as de novo predicted sequences. Experimentally validated and predicted epitopes were prioritized following a series of criteria that included evolutionary conservation, presence in the virulent and currently circulating variant Georgia 2007/1, and lack of identity to either the pig proteome or putative proteins from pig gut microbiota. Following this strategy, 29 B-cell, 14 CD4+ T-cell and 6 CD8+ T-cell epitopes were selected, which represent a starting point to investigating the protective capacity of ASFV epitope-based vaccines.

scholarly journals Approach to the unfolding and folding dynamics of add A-riboswitch upon adenine dissociation using a coarse-grained elastic network model

2016 ◽  
Vol 145 (1) ◽  
pp. 014104 ◽  
Author(s):  
Chunhua Li ◽  
Dashuai Lv ◽  
Lei Zhang ◽  
Feng Yang ◽  
Cunxin Wang ◽  
...  
Keyword(s):  
Network Model ◽  
Coarse Grained ◽  
Elastic Network Model ◽  
Elastic Network ◽  
Folding Dynamics

scholarly journals Recent Applications of Retro-Inverso Peptides

2021 ◽  
Vol 22 (16) ◽  
pp. 8677
Author(s):  
Nunzianna Doti ◽  
Mario Mardirossian ◽  
Annamaria Sandomenico ◽  
Menotti Ruvo ◽  
Andrea Caporale
Keyword(s):  
Amino Acids ◽  
Neurodegenerative Diseases ◽  
De Novo ◽  
3D Structure ◽  
New Drugs ◽  
Side Chains ◽  
Pros And Cons ◽  
Endogenous Proteases ◽  
Natural Amino Acids ◽  
Poor Stability

Natural and de novo designed peptides are gaining an ever-growing interest as drugs against several diseases. Their use is however limited by the intrinsic low bioavailability and poor stability. To overcome these issues retro-inverso analogues have been investigated for decades as more stable surrogates of peptides composed of natural amino acids. Retro-inverso peptides possess reversed sequences and chirality compared to the parent molecules maintaining at the same time an identical array of side chains and in some cases similar structure. The inverted chirality renders them less prone to degradation by endogenous proteases conferring enhanced half-lives and an increased potential as new drugs. However, given their general incapability to adopt the 3D structure of the parent peptides their application should be careful evaluated and investigated case by case. Here, we review the application of retro-inverso peptides in anticancer therapies, in immunology, in neurodegenerative diseases, and as antimicrobials, analyzing pros and cons of this interesting subclass of molecules.

scholarly journals De Novo Molecule Design Through Molecular Generative Model Conditioned by 3D Information of Protein Binding Sites

2020 ◽  
Author(s):  
Mingyuan Xu ◽  
Ting Ran ◽  
Hongming Chen
Keyword(s):  
Protein Binding ◽  
De Novo ◽  
Structural Information ◽  
Chemical Space ◽  
Three Dimensional ◽  
Binding Pocket ◽  
Generative Model ◽  
Coarse Grained ◽  
Molecule Design ◽  
3D Information

<p><i>De novo</i> molecule design through molecular generative model is gaining increasing attention in recent years. Here a novel generative model was proposed by integrating the 3D structural information of the protein binding pocket into the conditional RNN (cRNN) model to control the generation of drug-like molecules. In this model, the composition of protein binding pocket is effectively characterized through a coarse-grain strategy and the three-dimensional information of the pocket can be represented by the sorted eigenvalues of the coulomb matrix (EGCM) of the coarse-grained atoms composing the binding pocket. In current work, we used our EGCM method and a previously reported binding pocket descriptor DeeplyTough to train cRNN models and compared their performance. It has been shown that the molecules generated with the control of protein environment information have a clear tendency on generating compounds with higher similarity to the original X-ray bound ligand than normal RNN model and also achieving better performance in terms of docking scores. Our results demonstrate the potential application of EGCM controlled generative model for the targeted molecule generation and guided exploration on the drug-like chemical space. </p><p> </p>

Fast folding dynamics of an α-helical peptide with bulky side chains

2004 ◽  
Vol 6 (5) ◽  
pp. 1022-1030 ◽  
Author(s):  
Sarah A. Petty ◽  
Martin Volk
Keyword(s):  
Side Chains ◽  
Helical Peptide ◽  
Folding Dynamics

Self-Similarity of Protein Folding Flows

2012 ◽  
Vol 7 (4) ◽  
pp. 136-141
Author(s):  
I. Kalgin ◽  
Sergey Chekmarev
Keyword(s):  
Protein Folding ◽  
Sh3 Domain ◽  
Atomic Level ◽  
The Self ◽  
Coarse Grained ◽  
Folding Kinetics ◽  
Native State ◽  
Self Similarity ◽  
Folding Dynamics ◽  
Fractal Character

The problem of how a protein folds into its functional (native) state is one of the central problems of molecular biology, which attracts the attention of researchers from biology, physics and chemistry for many years. Of particular interest are general properties of the folding process, because the mechanisms of folding of different proteins can be essentially different. Previously, in the study of folding of fyn SH3 domain, we found that despite all the diversity and complexity of individual folding trajectories, the folding flows possess a well pronounced property of self-similarity, with a fractal character of the flow distributions. In the present paper, we study this phenomenon for another protein – beta3s, which is essentially different from the SH3 domain in its structure and folding kinetics. Also, in contrast to the fyn SH3 domain, for which a coarse-grained representation was used, we perform simulations on the atomic level of resolution. We show that the self-similarity and fractality of folding flows are observed is this case too, which suggests that these properties are characteristic of the protein folding dynamics

Uncertainty, Profit, and the Limits of Markets

2021 ◽  
pp. 106591292110358
Author(s):  
Roni Hirsch
Keyword(s):  
Allocative Efficiency ◽  
Market Model ◽  
Perfect Competition ◽  
Political Debate ◽  
Trade Off ◽  
Starting Point ◽  
Knowledge Uncertainty ◽  
Market Benefits ◽  
Capitalist Democracies ◽  
The Ideal

The neoclassical market model is the overwhelming basis for contemporary views of markets as fair, efficient, or both. But is it an appropriate starting point? The article draws on Frank Knight’s 1920s work on the economics of uncertainty to show that the ideal of perfect competition conceals a tacit trade-off between equality and certainty. Largely undetected, this trade-off continues to govern financialized capitalist democracies, evading normative and political debate. By explaining how markets and firms resolve the problem of uncertainty, Knight shows that all supposed market benefits, even allocative efficiency, are not costless to society. More specifically, Knight argued that modern markets are premised on a tacit agreement between a handful of “daring” entrepreneurs and the “risk-averse” public: the former agree to carry the uncertainties of business-life in return for a substantially larger share of its power and rewards. Despite the highly static assumptions of neoclassicism, therefore, and its linked assumption of perfect knowledge, uncertainty is far from absent in modern economics. It is built into firms and markets and manifests itself as a steep social and material hierarchy.

Comparison of neutral and charged polyelectrolyte bottlebrush polymers in dilute salt-free conditions

MRS Advances ◽  
2020 ◽  
Vol 5 (17) ◽  
pp. 899-906
Author(s):  
Alexandros Chremos ◽  
Ferenc Horkay
Keyword(s):  
Coarse Grained ◽  
Side Chains ◽  
Spring Model ◽  
Static Structure ◽  
Polymer Swelling ◽  
Additional Peak ◽  
Structure Factors ◽  
Explicit Solvent ◽  
Dynamics Simulations ◽  
Repulsive Forces

ABSTRACTWe investigate the structure of neutral and charged bottlebrush polymers in salt-free solutions at different polymer concentrations. In particular, we use molecular dynamics simulations by utilizing a coarse-grained bead-spring model that includes an explicit solvent and complementary experiments made by small angle neutron scattering (SANS). We find that the charged groups along the side chains exert significant repulsive forces, resulting in polymer swelling and backbone stretching. In addition to the primary polyelectrolyte peak, we find that bottlebrush polymers exhibit an additional peak in the form and static structure factors, a feature that is absent in neutral polymers. We show that this additional peak describes the intra-molecular correlations between the charged side chains.

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