A5044249043- Mass Spectrometry Techniques and Applications
- Viral Infections and Vectors
- Viral Infections and Outbreaks Research
- Advanced Proteomics Techniques and Applications
- interferon and immune responses
- Respiratory viral infections research
- Hepatitis B Virus Studies
- Metabolomics and Mass Spectrometry Studies
- Ubiquitin and proteasome pathways
- Monoclonal and Polyclonal Antibodies Research
- Protein Structure and Dynamics
- SARS-CoV-2 and COVID-19 Research
- Analytical Chemistry and Chromatography
- RNA modifications and cancer
- Peptidase Inhibition and Analysis
- RNA Research and Splicing
- Protein Degradation and Inhibitors
- Vector-borne infectious diseases
- Research on Leishmaniasis Studies
- RNA regulation and disease
- Toxoplasma gondii Research Studies
- Chemical Synthesis and Analysis
- Neuroinflammation and Neurodegeneration Mechanisms
- Viral gastroenteritis research and epidemiology
- Galectins and Cancer Biology
Washington University in St. Louis
2019-2025
Friedrich-Loeffler-Institut
2019-2020
Texas A&M University
2016-2018
Microglia help limit the progression of Alzheimer’s disease (AD) by constraining amyloid-β (Aβ) pathology, effected through a balance activating and inhibitory intracellular signals delivered distinct cell surface receptors. Human leukocyte Ig-like receptor B4 (LILRB4) is an immunoglobulin (Ig) superfamily that expressed on myeloid cells recognizes apolipoprotein E (ApoE) among other ligands. Here, we find LILRB4 highly in microglia patients with AD. Using mice accumulate Aβ carry transgene...
Molecular dynamics (MD) simulations are used to model changes in the conformational preferences of a peptide during transition from hydrated environment (charged nanodroplet generated by electrospray ionization) solvent-free ion. The charged droplet consists ∼2400 water molecules, 22 hydronium ions, and 10 chloride contains single Substance P (SP) [SP + 3H]3+ ion (SP3+; amino acid sequence RPKPQQFFGLM-NH2). Initially, shrinkage involves combination solvent evaporation ejection excess charge,...
Metallothioneins (MTs) constitute a group of intrinsically disordered proteins that exhibit extreme diversity in structure, biological functionality, and metal ion specificity. Structures coordinatively saturated metalated MTs have been extensively studied, but very limited structural information for the partially exists. Here, conformational preferences from partial metalation rabbit metallothionein-2A (MT) by Cd2+, Zn2+, Ag+ are studied using nanoelectrospray ionization mobility mass...
Electrospray ionization (ESI) of ubiquitin from acidified (0.1%) aqueous solution produces abundant ubiquitin-chloride adduct ions, [M + nH xCl]((n - x)+), that upon mild heating react via elimination neutral HCl. Ion mobility collision cross section (CCS) measurements show ions retaining chloride adducts exhibit CCS values similar to those the "native-state" protein. Coupled with results recent molecular dynamics (MD) simulations for evolution a salt-containing electrospray droplet, this...
Significance The human respiratory syncytial virus (RSV) is a significant cause of lower tract infections in the young and elderly substantial burden to global health. Currently, there are no specific effective treatments for RSV infections. Here we report first X-ray crystal structure nonstructural protein 2 (NS2), which revealed unique fold. combined biochemical structural analyses NS2 identified region that binds inhibits ubiquitination an inactive form RIG-I MDA5, preventing downstream...
Specific amino acid footprinting mass spectrometry (MS) is an increasingly utilized method for elucidating protein higher order structure (HOS). It does this by adding to certain residues a tag, whose reaction extent depends on solvent accessibility and microenvironment of the protein. Unlike reactive free radicals carbenes, these specific footprinters react slower than unfolding. Thus, their footprinting, under conditions, provokes structural changes protein, leading labeling non-native...
The Mediator complex facilitates interactions between transcription factors and RNA polymerase II, a process that is required for host gene transcription, including in response to viral infections. Among the many subunits complex, MED25 subunit has been shown be target activators during infection. Here we provide molecular basis interaction human respiratory syncytial virus (hRSV) nonstructural 1 protein (NS1) activator domain (ACID) of MED25. X-ray crystal structure revealed NS1 straddles...
Abstract The ability to inhibit host cell apoptosis is important for the intracellular replication of obligate pathogen Coxiella burnetii , as it allows completion lengthy bacterial cycle. Effector proteins injected into by C. type IVB secretion system (T4BSS) are required inhibition apoptosis. AnkG one these anti-apoptotic effector proteins. inhibitory effect requires its nuclear localization, which depends on p32-dependent trafficking and importin-α1-mediated entry AnkG. Here, we compared...
Protein footprinting mass spectrometry (MS), an emerging approach to elucidate higher-order structure (HOS) and binding, benefits from the iterative development of reaction strategies expand covalent labeling toolbox. Herein, we introduce a reagent for nucleophiles demonstrate its efficacy differential MS analysis. Benzoyl fluoride (BF), although reactive with water, is more practical modifying nucleophilic functional groups than other acid halides serves as acyl-transfer proteins. BF 10...
Understanding protein higher order structure and interfacial interactions is crucial to understanding binding motifs cellular function, that is, an interactome. Polyubiquitylation a post-translational modification functions as tag for diverse array of processes, wherein differences in chain length, branching, linkage site encode different functions. Investigation covalently linked diubiquitin (diUbq) molecules specifically selects the effect covalent on conformational preference molecule...
Covalently linked diubiquitin (diUbq) is known to adopt specific interfacial interactions owing steric hindrance induced by the covalent tether. K48-linked diUbq preferentially forms hydrophobic between two I44 faces under physiological conditions, whereas K63-linked electrostatic interactions. Here, we show using collision-induced unfolding ion mobility-mass spectrometry that recently reported noncovalent dimer of ubiquitin exhibits structural preferences and are most similar diUbq.
Marburg virus causes sporadic outbreaks of severe hemorrhagic fever with high case fatality rates. Approved, effective, and safe therapeutic or prophylactic countermeasures are lacking. To address this, we used phage display to engineer a synthetic antibody, sFab H3, which binds the VP35 protein (mVP35). mVP35 is critical cofactor viral replication complex immune antagonist. H3 displayed specificity for not closely related Ebola VP35. inhibited viral-RNA synthesis in minigenome assay,...
Summary Nucleocapsid protein (N) is the most abundant viral encoded by SARS-CoV-2, causative agent of COVID-19. N plays key roles at different steps in replication cycle and used as a serological marker infection. Here we characterize biochemical properties SARS-CoV-2 N. We define domains important for oligomerization RNA binding that are associated with spherical droplet formation suggest accessibility assembly may be regulated phosphorylation. also map interface using hydrogen-deuterium...
Isomeric octahedral osmium and rhenium complexes of formulas M(CO)y(X)z(P((CH2)n)3P) M(CO)y(X)z(P(CH2)n−1CH2)((CH2)n)(P(CH2)n−1CH2) (n/M/y/z/X = 14/Os/2/2/Cl, 14/Os/2/2/Br, 14/Re/3/1/Cl, 18/Os/2/2/Br), in which the phosphorus donor atoms occupy trans positions, are examined by title techniques. The former gyroscope-like spherical or ovoid shape, whereas latter have phosphacycle "flaps" that increase volume. Both types diffuse at identical rates C6D6 as assayed DOSY NMR, but ions derived from...
Protein footprinting mass spectrometry probes protein higher order structure and dynamics by labeling amino acid side-chains or backbone amides as a function of solvent accessibility. One category uses residue-specific, irreversible covalent modifications, affording flexibility sample processing for bottom-up analysis. Although several specific technologies are becoming established in structural proteomics, there remains need to assess fundamental properties new reagents before their...
Protein glycosylation is a common and highly heterogeneous post-translational modification that challenges biophysical characterization technologies. The heterogeneity of glycoproteins makes their structural analysis difficult; in particular, hydrogen–deuterium exchange mass spectrometry (HDX-MS) often suffers from poor sequence coverage near the site. A pertinent example Fc gamma receptor RIIIa (FcγRIIIa, CD16a), glycoprotein expressed on surface natural killer cells (NK) binds domain IgG...
Nipah virus (NiV) is an emerging and deadly zoonotic paramyxovirus that responsible for periodic epidemics of acute respiratory illness encephalitis in humans. Previous studies have shown the NiV V protein antagonizes host antiviral immunity, but molecular mechanism incompletely understood. To address this gap, we biochemically characterized binding to pattern recognition receptor MDA5. We find C-terminal domain (V
Protein footprinting is a mass spectrometry (MS)-based approach to measure protein conformational changes. One approach, specific amino acid labeling, imparts often an irreversible modification side chains but requires careful selection of the reactive reagent and time-consuming optimization experimental parameters prior submission bottom-up MS analysis. In this work, we repurpose hydrogen-deuterium exchange (HDX-MS) LEAP HDX system for automated MS, demonstrating its efficacy in reaction...
Viral inclusion bodies (IBs) are potential sites of viral replication and assembly.How IBs form remains poorly defined.Here we describe a combined biophysical cellular approach to identify the components necessary for IB formation during Ebola virus (EBOV) infection.We find that eNP 0 VP35 complex containing nucleoprotein (eNP) protein 35 (eVP35), functional equivalents (N) phosphoprotein (P) in non-segmented negative strand viruses (NNSVs), phase separates bodies.Phase separation is...
Nucleocapsid proteins are essential for SARS-CoV-2 life cycle. Here, we describe protocols to gather domain-specific insights about properties of nucleocapsids. These assays include dynamic light scattering characterize oligomerization, fluorescence polarization quantify RNA binding, hydrogen-deuterium exchange mass spectrometry map binding regions, negative-stain electron microscopy visualize oligomeric species, interferon reporter assay evaluate signaling modulation, and a serology reveal...