scholarly journals Allosteric inhibition of the SARS-CoV-2 main protease – insights from mass spectrometry-based assays

2020 ◽  
Author(s):  
Tarick J. El-Baba ◽  
Corinne A. Lutomski ◽  
Anastassia L. Kantsadi ◽  
Tika R. Malla ◽  
Tobias John ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Native Mass Spectrometry ◽  
Turnover Rates ◽  
Kinetic Assay ◽  
Antiviral Therapies ◽  
Enzyme Substrate ◽  
Main Protease ◽  
Starting Point ◽  
Catalytically Active ◽  
Substrate Processing

AbstractFollowing translation of the SARS-CoV-2 RNA genome into two viral polypeptides, the main protease Mpro cleaves at eleven sites to release non-structural proteins required for viral replication. MPro is an attractive target for antiviral therapies to combat the coronavirus-2019 disease (COVID-19). Here, we have used native mass spectrometry (MS) to characterize the functional unit of Mpro. Analysis of the monomer-dimer equilibria reveals a dissociation constant of Kd = 0.14 ± 0.03 μM, revealing MPro has a strong preference to dimerize in solution. Developing an MS-based kinetic assay we then characterized substrate turnover rates by following temporal changes in the enzyme-substrate complexes, which are effectively “flash-frozen” as they transition from solution to the gas phase. We screened small molecules, that bind distant from the active site, for their ability to modulate activity. These compounds, including one proposed to disrupt the catalytically active dimer, slow the rate of substrate processing by ~35%. This information was readily obtained and, together with analysis of the x-ray crystal structures of these enzyme-small molecule complexes, provides a starting point for the development of more potent molecules that allosterically regulate MPro activity.

scholarly journals Identifying Unknown Enzyme-Substrate Pairs from the Cellular Milieu with Native Mass Spectrometry

ChemBioChem ◽  
2017 ◽  
Vol 18 (7) ◽  
pp. 613-617 ◽  
Author(s):  
Kalli C. Catcott ◽  
Jing Yan ◽  
Wanlu Qu ◽  
Vicki H. Wysocki ◽  
Zhaohui Sunny Zhou
Keyword(s):  
Mass Spectrometry ◽  
Native Mass Spectrometry ◽  
Enzyme Substrate

scholarly journals SARS-CoV-2 Main Protease Active Site Ligands in the Human Metabolome

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1409
Author(s):  
Anna Maria Sardanelli ◽  
Camilla Isgrò ◽  
Luigi Leonardo Palese
Keyword(s):  
Active Site ◽  
Therapeutic Strategy ◽  
Silybum Marianum ◽  
Antiviral Therapies ◽  
Global Pandemic ◽  
Main Protease ◽  
Toxicological Profile ◽  
Starting Point ◽  
Antiviral Activities

In late 2019, a global pandemic occurred. The causative agent was identified as a member of the Coronaviridae family, called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this study, we present an analysis on the substances identified in the human metabolome capable of binding the active site of the SARS-CoV-2 main protease (Mpro). The substances present in the human metabolome have both endogenous and exogenous origins. The aim of this research was to find molecules whose biochemical and toxicological profile was known that could be the starting point for the development of antiviral therapies. Our analysis revealed numerous metabolites—including xenobiotics—that bind this protease, which are essential to the lifecycle of the virus. Among these substances, silybin, a flavolignan compound and the main active component of silymarin, is particularly noteworthy. Silymarin is a standardized extract of milk thistle, Silybum marianum, and has been shown to exhibit antioxidant, hepatoprotective, antineoplastic, and antiviral activities. Our results—obtained in silico and in vitro—prove that silybin and silymarin, respectively, are able to inhibit Mpro, representing a possible food-derived natural compound that is useful as a therapeutic strategy against COVID-19.

scholarly journals Cover Picture: Identifying Unknown Enzyme-Substrate Pairs from the Cellular Milieu with Native Mass Spectrometry (ChemBioChem 7/2017)

ChemBioChem ◽  
2017 ◽  
Vol 18 (7) ◽  
pp. 572-572
Author(s):  
Kalli C. Catcott ◽  
Jing Yan ◽  
Wanlu Qu ◽  
Vicki H. Wysocki ◽  
Zhaohui Sunny Zhou
Keyword(s):  
Mass Spectrometry ◽  
Native Mass Spectrometry ◽  
Enzyme Substrate

Rapid Online Buffer Exchange: A Method for Screening of Proteins, Protein Complexes, and Cell Lysates by Native Mass Spectrometry

2019 ◽  
Author(s):  
Zachary VanAernum ◽  
Florian Busch ◽  
Benjamin J. Jones ◽  
Mengxuan Jia ◽  
Zibo Chen ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Speed ◽  
Structural Information ◽  
Protein Complexes ◽  
High Sensitivity ◽  
Native Mass Spectrometry ◽  
Structural Features ◽  
Consumer Products ◽  
Cell Lysates ◽  
Protein Expression And Purification

It is important to assess the identity and purity of proteins and protein complexes during and after protein purification to ensure that samples are of sufficient quality for further biochemical and structural characterization, as well as for use in consumer products, chemical processes, and therapeutics. Native mass spectrometry (nMS) has become an important tool in protein analysis due to its ability to retain non-covalent interactions during measurements, making it possible to obtain protein structural information with high sensitivity and at high speed. Interferences from the presence of non-volatiles are typically alleviated by offline buffer exchange, which is timeconsuming and difficult to automate. We provide a protocol for rapid online buffer exchange (OBE) nMS to directly screen structural features of pre-purified proteins, protein complexes, or clarified cell lysates. Information obtained by OBE nMS can be used for fast (<5 min) quality control and can further guide protein expression and purification optimization.

Native Mass Spectrometry-Based Screening for Optimal Sample Preparation in Single Particle Cryo-EM

2020 ◽  
Author(s):  
Paul Dominic B. Olinares ◽  
Jin Young Kang ◽  
Eliza Llewellyn ◽  
Courtney Chiu ◽  
James Chen ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Sample Preparation ◽  
Single Particle ◽  
Native Mass Spectrometry ◽  
Optimal Sample

scholarly journals DNA G-quadruplexes for native mass spectrometry in potassium: a database of validated structures in electrospray-compatible conditions

2021 ◽  
Author(s):  
Anirban Ghosh ◽  
Eric Largy ◽  
Valérie Gabelica
Keyword(s):  
Mass Spectrometry ◽  
Drug Targets ◽  
Native Mass Spectrometry ◽  
Drug Binding ◽  
Quadruplex Dna ◽  
Dna Structures ◽  
Nmr Structures ◽  
G Quadruplex ◽  
Screening Assays

Abstract G-quadruplex DNA structures have become attractive drug targets, and native mass spectrometry can provide detailed characterization of drug binding stoichiometry and affinity, potentially at high throughput. However, the G-quadruplex DNA polymorphism poses problems for interpreting ligand screening assays. In order to establish standardized MS-based screening assays, we studied 28 sequences with documented NMR structures in (usually ∼100 mM) potassium, and report here their circular dichroism (CD), melting temperature (Tm), NMR spectra and electrospray mass spectra in 1 mM KCl/100 mM trimethylammonium acetate. Based on these results, we make a short-list of sequences that adopt the same structure in the MS assay as reported by NMR, and provide recommendations on using them for MS-based assays. We also built an R-based open-source application to build and consult a database, wherein further sequences can be incorporated in the future. The application handles automatically most of the data processing, and allows generating custom figures and reports. The database is included in the g4dbr package (https://github.com/EricLarG4/g4dbr) and can be explored online (https://ericlarg4.github.io/G4_database.html).

scholarly journals Development of a target identification approach using native mass spectrometry

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Miaomiao Liu ◽  
Wesley C. Van Voorhis ◽  
Ronald J. Quinn
Keyword(s):  
Mass Spectrometry ◽  
Protein Interactions ◽  
Target Identification ◽  
Native Mass Spectrometry ◽  
Pharmaceutical Drugs ◽  
Ligand Complex ◽  
Experimental Conditions ◽  
Protein Mixture ◽  
Native Ms ◽  
Drug Target Identification

AbstractA key step in the development of new pharmaceutical drugs is the identification of the molecular target and distinguishing this from all other gene products that respond indirectly to the drug. Target identification remains a crucial process and a current bottleneck for advancing hits through the discovery pipeline. Here we report a method, that takes advantage of the specific detection of protein–ligand complexes by native mass spectrometry (MS) to probe the protein partner of a ligand in an untargeted method. The key advantage is that it uses unmodified small molecules for binding and, thereby, it does not require labelled ligands and is not limited by the chemistry required to tag the molecule. We demonstrate the use of native MS to identify known ligand–protein interactions in a protein mixture under various experimental conditions. A protein–ligand complex was successfully detected between parthenolide and thioredoxin (PfTrx) in a five-protein mixture, as well as when parthenolide was mixed in a bacterial cell lysate spiked with PfTrx. We provide preliminary data that native MS could be used to identify binding targets for any small molecule.

scholarly journals Benchmarking Non-Targeted Metabolomics Using Yeast-Derived Libraries

Metabolites ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 160
Author(s):  
Evelyn Rampler ◽  
Gerrit Hermann ◽  
Gerlinde Grabmann ◽  
Yasin El Abiead ◽  
Harald Schoeny ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Quality Control ◽  
Protein Identification ◽  
Regulatory Elements ◽  
Yeast Fermentation ◽  
Compound Identification ◽  
Targeted Metabolomics ◽  
Targeted Analysis ◽  
Orthogonal State ◽  
Starting Point

Non-targeted analysis by high-resolution mass spectrometry (HRMS) is an essential discovery tool in metabolomics. To date, standardization and validation remain a challenge. Community-wide accepted cost-effective benchmark materials are lacking. In this work, we propose yeast (Pichia pastoris) extracts derived from fully controlled fermentations for this purpose. We established an open-source metabolite library of >200 identified metabolites based on compound identification by accurate mass, matching retention times, and MS/MS, as well as a comprehensive literature search. The library includes metabolites from the classes of (1) organic acids and derivatives (2) nucleosides, nucleotides, and analogs, (3) lipids and lipid-like molecules, (4) organic oxygen compounds, (5) organoheterocyclic compounds, (6) organic nitrogen compounds, and (7) benzoids at expected concentrations ranges of sub-nM to µM. As yeast is a eukaryotic organism, key regulatory elements are highly conserved between yeast and all annotated metabolites were also reported in the human metabolome database (HMDB). Orthogonal state-of-the-art reversed-phase (RP-) and hydrophilic interaction chromatography mass spectrometry (HILIC-MS) non-targeted analysis and authentic standards revealed that 104 out of the 206 confirmed metabolites were reproducibly recovered and stable over the course of three years when stored at −80 °C. Overall, 67 out of these 104 metabolites were identified with comparably stable areas over all three yeast fermentation and are the ideal starting point for benchmarking experiments. The provided yeast benchmark material enabled not only to test for the chemical space and coverage upon method implementation and developments but also allowed in-house routines for instrumental performance tests. Transferring the quality control strategy of proteomics workflows based on the number of protein identification in HeLa extracts, metabolite IDs in the yeast benchmarking material can be used as metabolomics quality control. Finally, the benchmark material opens new avenues for batch-to-batch corrections in large-scale non-targeted metabolomics studies.

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