scholarly journals Native mass spectrometry identifies the HybG chaperone as carrier of the Fe(CN)2CO group during maturation of E. coli [NiFe]-hydrogenase 2

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christian Arlt ◽  
Kerstin Nutschan ◽  
Alexander Haase ◽  
Christian Ihling ◽  
Dirk Tänzler ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Native Mass Spectrometry ◽  
Cysteine Residue ◽  
Catalytic Subunit ◽  
Accessory Proteins ◽  
Catalytic Subunits ◽  
E Coli ◽  
Client Proteins ◽  
Covalent Modifications ◽  
Hydrogenase 2

Abstract[NiFe]-hydrogenases activate dihydrogen. Like all [NiFe]-hydrogenases, hydrogenase 2 of Escherichia coli has a bimetallic NiFe(CN)2CO cofactor in its catalytic subunit. Biosynthesis of the Fe(CN)2CO group of the [NiFe]-cofactor occurs on a distinct scaffold complex comprising the HybG and HypD accessory proteins. HybG is a member of the HypC-family of chaperones that confers specificity towards immature hydrogenase catalytic subunits during transfer of the Fe(CN)2CO group. Using native mass spectrometry of an anaerobically isolated HybG–HypD complex we show that HybG carries the Fe(CN)2CO group. Our results also reveal that only HybG, but not HypD, interacts with the apo-form of the catalytic subunit. Finally, HybG was shown to have two distinct, and apparently CO2-related, covalent modifications that depended on the presence of the N-terminal cysteine residue on the protein, possibly representing intermediates during Fe(CN)2CO group biosynthesis. Together, these findings suggest that the HybG chaperone is involved in both biosynthesis and delivery of the Fe(CN)2CO group to its target protein. HybG is thus suggested to shuttle between the assembly complex and the apo-catalytic subunit. This study provides new insights into our understanding of how organometallic cofactor components are assembled on a scaffold complex and transferred to their client proteins.

scholarly journals Structural insights into Escherichia coli phosphopantothenoylcysteine synthetase by native ion mobility–mass spectrometry

2019 ◽  
Vol 476 (21) ◽  
pp. 3125-3139 ◽  
Author(s):  
Daniel Shiu-Hin Chan ◽  
Jeannine Hess ◽  
Elen Shaw ◽  
Christina Spry ◽  
Robert Starley ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Escherichia Coli ◽  
Structural Biology ◽  
Ion Mobility ◽  
Biosynthetic Pathway ◽  
Screening Tool ◽  
Native Mass Spectrometry ◽  
Ion Mobility Mass Spectrometry ◽  
E Coli ◽  
Structural Insights

Abstract CoaBC, part of the vital coenzyme A biosynthetic pathway in bacteria, has recently been validated as a promising antimicrobial target. In this work, we employed native ion mobility–mass spectrometry to gain structural insights into the phosphopantothenoylcysteine synthetase domain of E. coli CoaBC. Moreover, native mass spectrometry was validated as a screening tool to identify novel inhibitors of this enzyme, highlighting the utility and versatility of this technique both for structural biology and for drug discovery.

scholarly journals Characterization of trimethoprim resistant E. coli dihydrofolate reductase mutants by mass spectrometry and inhibition by propargyl-linked antifolates

2017 ◽  
Vol 8 (5) ◽  
pp. 4062-4072 ◽  
Author(s):  
Michael Cammarata ◽  
Ross Thyer ◽  
Michael Lombardo ◽  
Amy Anderson ◽  
Dennis Wright ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Size Exclusion Chromatography ◽  
Dihydrofolate Reductase ◽  
Native Mass Spectrometry ◽  
Size Exclusion ◽  
E Coli ◽  
Exclusion Chromatography

Native mass spectrometry, size exclusion chromatography, and kinetic assays were employed to study trimethoprim resistance in E. coli caused by mutations P21L and W30R of dihydrofolate reductase.

scholarly journals Native Tandem and Ion Mobility Mass Spectrometry Highlight Structural and Modular Similarities in Clustered-Regularly-Interspaced Shot-Palindromic-Repeats (CRISPR)-associated Protein Complexes From Escherichia coli and Pseudomonas aeruginosa

2012 ◽  
Vol 11 (11) ◽  
pp. 1430-1441 ◽  
Author(s):  
Esther van Duijn ◽  
Ioana M. Barbu ◽  
Arjan Barendregt ◽  
Matthijs M. Jore ◽  
Blake Wiedenheft ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Ion Mobility ◽  
Protein Complexes ◽  
Acquired Resistance ◽  
Native Mass Spectrometry ◽  
Ion Mobility Mass Spectrometry ◽  
E Coli ◽  
Ribonucleoprotein Complexes ◽  
Specific Association

The CRISPR/Cas (clustered regularly interspaced short palindromic repeats/CRISPR-associated genes) immune system of bacteria and archaea provides acquired resistance against viruses and plasmids, by a strategy analogous to RNA-interference. Key components of the defense system are ribonucleoprotein complexes, the composition of which appears highly variable in different CRISPR/Cas subtypes. Previous studies combined mass spectrometry, electron microscopy, and small angle x-ray scattering to demonstrate that the E. coli Cascade complex (405 kDa) and the P. aeruginosa Csy-complex (350 kDa) are similar in that they share a central spiral-shaped hexameric structure, flanked by associating proteins and one CRISPR RNA. Recently, a cryo-electron microscopy structure of Cascade revealed that the CRISPR RNA molecule resides in a groove of the hexameric backbone. For both complexes we here describe the use of native mass spectrometry in combination with ion mobility mass spectrometry to assign a stable core surrounded by more loosely associated modules. Via computational modeling subcomplex structures were proposed that relate to the experimental IMMS data. Despite the absence of obvious sequence homology between several subunits, detailed analysis of sub-complexes strongly suggests analogy between subunits of the two complexes. Probing the specific association of E. coli Cascade/crRNA to its complementary DNA target reveals a conformational change. All together these findings provide relevant new information about the potential assembly process of the two CRISPR-associated complexes.

Optics-Free Visualization of Proteins in Single Cells by Time of Flight-Secondary Ion Mass Spectrometry Coupled with Genetically Encoded Chemical Tags

2020 ◽  
Author(s):  
Feifei Jia ◽  
Jie Wang ◽  
Yanyan Zhang ◽  
Qun Luo ◽  
Luyu Qi ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Single Cells ◽  
Time Of Flight ◽  
E Coli ◽  
Tof Sims ◽  
Ion Mass Spectrometry ◽  
Chemical Tags ◽  
Secondary Ion

<p></p><p><i>In situ</i> visualization of proteins of interest at single cell level is attractive in cell biology, molecular biology and biomedicine, which usually involves photon, electron or X-ray based imaging methods. Herein, we report an optics-free strategy that images a specific protein in single cells by time of flight-secondary ion mass spectrometry (ToF-SIMS) following genetic incorporation of fluorine-containing unnatural amino acids as a chemical tag into the protein via genetic code expansion technique. The method was developed and validated by imaging GFP in E. coli and human HeLa cancer cells, and then utilized to visualize the distribution of chemotaxis protein CheA in E. coli cells and the interaction between high mobility group box 1 protein and cisplatin damaged DNA in HeLa cells. The present work highlights the power of ToF-SIMS imaging combined with genetically encoded chemical tags for <i>in situ </i>visualization of proteins of interest as well as the interactions between proteins and drugs or drug damaged DNA in single cells.</p><p></p>

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 Protein Kinase A Distribution in Meningioma

Cancers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1686 ◽  
Author(s):  
Caretta ◽  
Denaro ◽  
D’Avella ◽  
Mucignat-Caretta
Keyword(s):  
Brain Tissue ◽  
Catalytic Subunit ◽  
Therapeutic Interventions ◽  
Normal Brain ◽  
Local Concentration ◽  
Correlation Pattern ◽  
Catalytic Subunits ◽  
Tissue Specimens ◽  
Pka Catalytic Subunit

Deregulation of intracellular signal transduction pathways is a hallmark of cancer cells, clearly differentiating them from healthy cells. Differential intracellular distribution of the cAMP-dependent protein kinases (PKA) was previously detected in cell cultures and in vivo in glioblastoma and medulloblastoma. Our goal is to extend this observation to meningioma, to explore possible differences among tumors of different origins and prospective outcomes. The distribution of regulatory and catalytic subunits of PKA has been examined in tissue specimens obtained during surgery from meningioma patients. PKA RI subunit appeared more evenly distributed throughout the cytoplasm, but it was clearly detectable only in some tumors. RII was present in discrete spots, presumably at high local concentration; these aggregates could also be visualized under equilibrium binding conditions with fluorescent 8-substituted cAMP analogues, at variance with normal brain tissue and other brain tumors. The PKA catalytic subunit showed exactly overlapping pattern to RII and in fixed sections could be visualized by fluorescent cAMP analogues. Gene expression analysis showed that the PKA catalytic subunit revealed a significant correlation pattern with genes involved in meningioma. Hence, meningioma patients show a distinctive distribution pattern of PKA regulatory and catalytic subunits, different from glioblastoma, medulloblastoma, and healthy brain tissue. These observations raise the possibility of exploiting the PKA intracellular pathway as a diagnostic tool and possible therapeutic interventions.

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.

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