scholarly journals qFit-ligand reveals widespread conformational heterogeneity of drug-like molecules in X-ray electron density maps

2018 ◽  
Author(s):  
Gydo C.P. van Zundert ◽  
Brandi M. Hudson ◽  
Daniel A. Keedy ◽  
Rasmus Fonseca ◽  
Amelie Heliou ◽  
...  
Keyword(s):  
Drug Design ◽  
Crystal Structures ◽  
High Throughput Screening ◽  
Computational Method ◽  
Protein Crystal ◽  
Conformational Ensemble ◽  
Large Set ◽  
Conformational Heterogeneity ◽  
Structure Based Drug Design ◽  
X Ray

AbstractProteins and ligands sample a conformational ensemble that governs molecular recognition, activity, and dissociation. In structure-based drug design, access to this conformational ensemble is critical to understand the balance between entropy and enthalpy in lead optimization. However, ligand conformational heterogeneity is currently severely underreported in crystal structures in the Protein Data Bank, owing in part to a lack of automated and unbiased procedures to model an ensemble of protein-ligand states into X-ray data. Here, we designed a computational method, qFit-ligand, to automatically resolve conformationally averaged ligand heterogeneity in crystal structures, and applied it to a large set of protein receptor-ligand complexes. We found that up to 29 % of a dataset of protein crystal structures bound with drug-like molecules present evidence of unmodeled, averaged, relatively isoenergetic conformations in ligand-receptor interactions. In many retrospective cases, these alternate conformations were adventitiously exploited to guide compound design, resulting in improved potency or selectivity. Combining qFit-ligand with high-throughput screening or multi-temperature crystallography could therefore augment the structure-based drug design toolbox.

scholarly journals Crystal structures of human ENPP1 in apo and bound forms

2020 ◽  
Vol 76 (9) ◽  
pp. 889-898 ◽  
Author(s):  
Matthew L. Dennis ◽  
Janet Newman ◽  
Olan Dolezal ◽  
Meghan Hattarki ◽  
Regina N. Surjadi ◽  
...  
Keyword(s):  
Immune System ◽  
Drug Design ◽  
Crystal Structures ◽  
Cyclic Gmp ◽  
Therapeutic Target ◽  
Structure Based Drug Design ◽  
X Ray ◽  
Crystallization System ◽  
Causes Of Mortality ◽  
Cancerous Cells

Cancer is one of the leading causes of mortality in humans, and recent work has focused on the area of immuno-oncology, in which the immune system is used to specifically target cancerous cells. Ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) is an emerging therapeutic target in human cancers owing to its role in degrading cyclic GMP-AMP (cGAMP), an agonist of the stimulator of interferon genes (STING). The available structures of ENPP1 are of the mouse enzyme, and no structures are available with anything other than native nucleotides. Here, the first X-ray crystal structures of the human ENPP1 enzyme in an apo form, with bound nucleotides and with two known inhibitors are presented. The availability of these structures and a robust crystallization system will allow the development of structure-based drug-design campaigns against this attractive cancer therapeutic target.

scholarly journals High-resolution crystal structures of the D1 and D2 domains of protein tyrosine phosphatase epsilon for structure-based drug design

2018 ◽  
Vol 74 (10) ◽  
pp. 1015-1026 ◽  
Author(s):  
George T. Lountos ◽  
Sreejith Raran-Kurussi ◽  
Bryan M. Zhao ◽  
Beverly K. Dyas ◽  
Terrence R. Burke ◽  
...  
Keyword(s):  
Drug Design ◽  
Crystal Structures ◽  
Phosphatase Activity ◽  
Protein Tyrosine Phosphatase ◽  
High Throughput Screening ◽  
Catalytic Domain ◽  
Tyrosine Phosphatase ◽  
Triple Mutant ◽  
Structure Based Drug Design ◽  
Protein Tyrosine

Here, new crystal structures are presented of the isolated membrane-proximal D1 and distal D2 domains of protein tyrosine phosphatase epsilon (PTP∊), a protein tyrosine phosphatase that has been shown to play a positive role in the survival of human breast cancer cells. A triple mutant of the PTP∊ D2 domain (A455N/V457Y/E597D) was also constructed to reconstitute the residues of the PTP∊ D1 catalytic domain that are important for phosphatase activity, resulting in only a slight increase in the phosphatase activity compared with the native D2 protein. The structures reported here are of sufficient resolution for structure-based drug design, and a microarray-based assay for high-throughput screening to identify small-molecule inhibitors of the PTP∊ D1 domain is also described.

Hybrid Quantum Mechanics/Molecular Mechanics (QM/MM) Simulation: A Tool for Structure-based Drug Design and Discovery

2021 ◽  
Vol 21 ◽  
Author(s):  
Prajakta U. Kulkarni ◽  
Harshil Shah ◽  
Vivek K. Vyas
Keyword(s):  
Quantum Mechanics ◽  
Drug Design ◽  
Molecular Mechanics ◽  
Chemical Reactions ◽  
Classical Mechanics ◽  
Molecular Structures ◽  
Protein Crystal ◽  
Structure Based Drug Design ◽  
Structure And Property ◽  
Qsar Models

: Quantum mechanics (QM) is physics based theory which explains the physical properties of nature at the level of atoms and sub-atoms. Molecular mechanics (MM) construct molecular systems through the use of classical mechanics. So, hybrid quantum mechanics and molecular mechanics (QM/MM) when combined together can act as computer-based methods which can be used to calculate structure and property data of molecular structures. Hybrid QM/MM combines the strengths of QM with accuracy and MM with speed. QM/MM simulation can also be applied for the study of chemical process in solutions as well as in the proteins, and has a great scope in structure-based drug design (CADD) and discovery. Hybrid QM/MM also applied to HTS, to derive QSAR models and due to availability of many protein crystal structures; it has a great role in computational chemistry, especially in structure- and fragment-based drug design. Fused QM/MM simulations have been developed as a widespread method to explore chemical reactions in condensed phases. In QM/MM simulations, the quantum chemistry theory is used to treat the space in which the chemical reactions occur; however the rest is defined through molecular mechanics force field (MMFF). In this review, we have extensively reviewed recent literature pertaining to the use and applications of hybrid QM/MM simulations for ligand and structure-based computational methods for the design and discovery of therapeutic agents.

scholarly journals Structure-based drug design against Trypanosoma brucei methionyl-tRNA synthetase

2014 ◽  
Vol 70 (a1) ◽  
pp. C708-C708
Author(s):  
Cho Yeow Koh ◽  
Jasmine Nguyen ◽  
Sayaka Shibata ◽  
Zhongsheng Zhang ◽  
Ranae Ranade ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Trypanosoma Brucei ◽  
High Throughput ◽  
High Throughput Screening ◽  
Protozoan Parasite ◽  
Trna Synthetase ◽  
Structure Based Drug Design ◽  
Chemical Structures ◽  
Ic50 Values ◽  
Methionyl Trna Synthetase

Infection by the protozoan parasite Trypanosoma brucei causes human African trypanosomiasis, commonly known as sleeping sickness. The disease is fatal without treatment; yet, current therapeutic options for the disease are inadequate due to toxicity, difficulty in administration and emerging resistance. Therefore, methionyl-tRNA synthetase of T. brucei (TbMetRS) is targeted for the development of new antitrypanosomal drugs. We have recently completed a high-throughput screening campaign against TbMetRS using a 364,131 compounds library in The Scripps Research Institute Molecular Screening Center. Here we outline our strategy to integrate the power of crystal structures with high-throughput screening in a drug discovery project. We applied the rapid crystal soaking procedure to obtain structures of TbMetRS in complex with inhibitors reported earlier[1] to approximately 70 high-throughput screening hits. This resulted in more than 20 crystal structures of TbMetRS·hit complexes. These hits cover a large diversity of chemical structures with IC50 values between 200 nM and 10 µM. Based on the solved structures and existing knowledge drawn from other in-house inhibitors, the IC50 value of the most promising hit has been improved. Further development of the compounds into potent TbMetRS inhibitors with desirable pharmacokinetic properties is on-going and will continue to benefit from information derived from crystal structures.

Protein-Ligand Docking Methodologies and Its Application in Drug Discovery

2016 ◽  
pp. 196-219
Author(s):  
Sanchaita Rajkhowa ◽  
Ramesh C. Deka
Keyword(s):  
Molecular Docking ◽  
Drug Discovery ◽  
Drug Design ◽  
High Throughput Screening ◽  
Docking Studies ◽  
Stable Complex ◽  
Scoring Functions ◽  
Binding Modes ◽  
Structure Based Drug Design ◽  
Modern Drug

Molecular docking is a key tool in structural biology and computer-assisted drug design. Molecular docking is a method which predicts the preferred orientation of a ligand when bound in an active site to form a stable complex. It is the most common method used as a structure-based drug design. Here, the authors intend to discuss the various types of docking methods and their development and applications in modern drug discovery. The important basic theories such as sampling algorithm and scoring functions have been discussed briefly. The performances of the different available docking software have also been discussed. This chapter also includes some application examples of docking studies in modern drug discovery such as targeted drug delivery using carbon nanotubes, docking of nucleic acids to find the binding modes and a comparative study between high-throughput screening and structure-based virtual screening.

scholarly journals The critical role of QM/MM X-ray refinement and accurate tautomer/protomer determination in structure-based drug design

2020 ◽  
Author(s):  
Oleg Y. Borbulevych ◽  
Roger I. Martin ◽  
Lance M. Westerhoff
Keyword(s):  
Drug Design ◽  
Critical Role ◽  
Pharmaceutical Research ◽  
Energy Functional ◽  
Structural Refinement ◽  
Structure Based Drug Design ◽  
X Ray ◽  
X Ray Crystallography ◽  
Refinement Method ◽  
The Impact

Abstract Conventional protein:ligand crystallographic refinement uses stereochemistry restraints coupled with a rudimentary energy functional to ensure the correct geometry of the model of the macromolecule—along with any bound ligand(s)—within the context of the experimental, X-ray density. These methods generally lack explicit terms for electrostatics, polarization, dispersion, hydrogen bonds, and other key interactions, and instead they use pre-determined parameters (e.g. bond lengths, angles, and torsions) to drive structural refinement. In order to address this deficiency and obtain a more complete and ultimately more accurate structure, we have developed an automated approach for macromolecular refinement based on a two layer, QM/MM (ONIOM) scheme as implemented within our DivCon Discovery Suite and "plugged in" to two mainstream crystallographic packages: PHENIX and BUSTER. This implementation is able to use one or more region layer(s), which is(are) characterized using linear-scaling, semi-empirical quantum mechanics, followed by a system layer which includes the balance of the model and which is described using a molecular mechanics functional. In this work, we applied our Phenix/DivCon refinement method—coupled with our XModeScore method for experimental tautomer/protomer state determination—to the characterization of structure sets relevant to structure-based drug design (SBDD). We then use these newly refined structures to show the impact of QM/MM X-ray refined structure on our understanding of function by exploring the influence of these improved structures on protein:ligand binding affinity prediction (and we likewise show how we use post-refinement scoring outliers to inform subsequent X-ray crystallographic efforts). Through this endeavor, we demonstrate a computational chemistry ↔ structural biology (X-ray crystallography) "feedback loop" which has utility in industrial and academic pharmaceutical research as well as other allied fields.

scholarly journals Structure of human tankyrase 1 in complex with small-molecule inhibitors PJ34 and XAV939

2012 ◽  
Vol 68 (2) ◽  
pp. 115-118 ◽  
Author(s):  
Christina A. Kirby ◽  
Atwood Cheung ◽  
Aleem Fazal ◽  
Michael D. Shultz ◽  
Travis Stams
Keyword(s):  
Drug Design ◽  
Crystal Structures ◽  
Small Molecule ◽  
Small Molecule Inhibitors ◽  
Donor Site ◽  
Structure Based Drug Design ◽  
Crystallization System ◽  
Tankyrase 1

The crystal structures of tankyrase 1 (TNKS1) in complex with two small-molecule inhibitors, PJ34 and XAV939, both at 2.0 Å resolution, are reported. The structure of TNKS1 in complex with PJ34 reveals two molecules of PJ34 bound in the NAD+donor pocket. One molecule is in the nicotinamide portion of the pocket, as previously observed in other PARP structures, while the second molecule is bound in the adenosine portion of the pocket. Additionally, unlike the unliganded crystallization system, the TNKS1–PJ34 crystallization system has the NAD+donor site accessible to bulk solvent in the crystal, which allows displacement soaking. The TNKS1–PJ34 crystallization system was used to determine the structure of TNKS1 in complex with XAV939. These structures provide a basis for the start of a structure-based drug-design campaign for TNKS1.

scholarly journals Evaluating Unexpectedly Short Non-covalent Distances in X-ray Crystal Structures of Proteins with Electronic Structure Analysis

2019 ◽  
Author(s):  
Helena W. Qi ◽  
Heather Kulik
Keyword(s):  
Amino Acids ◽  
High Resolution ◽  
Crystal Structures ◽  
Close Contact ◽  
Protein Structures ◽  
Protein Crystal ◽  
X Ray ◽  
High Quality Protein ◽  
Van Der Waals Radii ◽  
Close Contacts

<div><div><div><p>We investigate unexpectedly short non-covalent distances (< 85% of the sum of van der Waals radii) in atomically resolved X-ray crystal structures of proteins. We curate over 13,000 high quality protein crystal structures and an ultra-high resolution (1.2 Å or better) subset containing > 1,000 structures. Although our non-covalent distance criterion excludes standard hydrogen bonds known to be essential in protein stability, we observe over 82,000 close contacts in the curated protein structures. Analysis of the frequency of amino acids participating in these interactions demonstrates some expected trends (i.e., enrichment of charged Lys, Arg, Asp, and Glu) but also reveals unexpected enhancement of Tyr in such interactions. Nearly all amino acids are observed to form at least one close contact with all other amino acids, and most interactions are preserved in the much smaller ultra high-resolution subset. We quantum-mechanically characterize the interaction energetics of a subset of > 6,000 close contacts with symmetry adapted perturbation theory to enable decomposition of interactions. We observe the majority of close contacts to be favorable. The shortest favorable non-covalent distances are under 2.2 Å and are very repulsive when characterized with classical force fields. This analysis reveals stabilization by a combination of electrostatic and charge transfer effects between hydrophobic (i.e., Val, Ile, Leu) amino acids and charged Asp or Glu. We also observe a unique hydrogen bonding configuration between Tyr and Asn/Gln involving both residues acting simultaneously as hydrogen bond donors and acceptors. This work confirms the importance of first-principles simulation in explaining unexpected geometries in protein crystal structures.</p></div></div></div>

scholarly journals Structure-Based Drug Design of an Inhibitor of the SARS-CoV-2 (COVID-19) Main Protease Using Free Software: A Tutorial for Students and Scientists

2020 ◽  
Author(s):  
Sheng Zhang ◽  
Maj Krumberger ◽  
Michael A. Morris ◽  
Chelsea Marie T. Parrocha ◽  
James H. Griffin ◽  
...  
Keyword(s):  
Drug Design ◽  
Cyclic Peptide ◽  
Free Software ◽  
New Drugs ◽  
Peptide Inhibitor ◽  
Drug Candidate ◽  
Crystallographic Structure ◽  
Structure Based Drug Design ◽  
X Ray ◽  
Main Protease

This paper describes the structure-based design of a preliminary drug candidate against COVID-19 using free software and publicly available X-ray crystallographic structures. The goal of this tutorial is to disseminate skills in structure-based drug design and to allow others to unleash their own creativity to design new drugs to fight the current pandemic. The tutorial begins with the X-ray crystallographic structure of the main protease (M<sup>pro</sup>) of the SARS coronavirus (SARS-CoV) bound to a peptide substrate and then uses the UCSF Chimera software to modify the substrate to create a cyclic peptide inhibitor within the M<sup>pro</sup> active site. Finally, the tutorial uses the molecular docking software AutoDock Vina to show the interaction of the cyclic peptide inhibitor with both SARS-CoV M<sup>pro</sup> and the highly homologous SARS-CoV-2 M<sup>pro</sup>. The supporting information (supplementary material) provides an illustrated step-by-step protocol, as well as a video showing the inhibitor design process, to help readers design their own drug candidates for COVID-19 and the coronaviruses that will cause future pandemics. An accompanying preprint in bioRxiv [https://doi.org/10.1101/2020.08.03.234872] describes the synthesis of the cyclic peptide and the experimental validation as an inhibitor of SARS-CoV-2 M<sup>pro</sup>.

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