A5056599790- Bacillus and Francisella bacterial research
- Bacterial Genetics and Biotechnology
- Protein Structure and Dynamics
- Enzyme Structure and Function
- Bacteriophages and microbial interactions
- Yersinia bacterium, plague, ectoparasites research
- Mass Spectrometry Techniques and Applications
- Microbial Inactivation Methods
- Photosynthetic Processes and Mechanisms
- Microbial Metabolic Engineering and Bioproduction
- Lipid Membrane Structure and Behavior
- Peptidase Inhibition and Analysis
- Poxvirus research and outbreaks
- Neutrophil, Myeloperoxidase and Oxidative Mechanisms
- Ubiquitin and proteasome pathways
- Inflammasome and immune disorders
- Phagocytosis and Immune Regulation
- RNA and protein synthesis mechanisms
- Electrohydrodynamics and Fluid Dynamics
- Heme Oxygenase-1 and Carbon Monoxide
- Advanced X-ray Imaging Techniques
- Cancer Research and Treatments
- Nicotinic Acetylcholine Receptors Study
- Inflammatory mediators and NSAID effects
- Advanced Electron Microscopy Techniques and Applications
University of Maryland, Baltimore
2015-2024
University of California, Berkeley
2009-2015
QB3
2009-2012
Institute of Molecular and Cell Biology
2009-2012
Urology of Virginia
2011
University of Chicago
2000-2006
Harvard University
2004-2006
Clemson University
2006
Parsons (United States)
2005
Albert Einstein College of Medicine
2005
Ubiquitin C-terminal hydrolases (UCH) are deubiquitinating enzymes which hydrolyze esters and amides of ubiquitin. Here we report the processing a number ubiquitin derivatives by two human UCH isozymes (isozymes L1 L3) find that these show little discrimination based on P1' amino acid, except proline is cleaved slowly. Ubiquitinyllysine linked α- or ε-amino group hydrolyzed at identical rates. Isozyme-specific hydrolytic preferences only evident when leaving large. The gene products can be...
Inflammasomes activate caspase-1 in response to cytosolic contamination or perturbation. This inflammatory caspase triggers the opening of GSDMD pore plasma membrane, resulting lytic cell death called pyroptosis. We had previously assumed that pyroptosis releases intracellular bacteria extracellular space. Here, we find viable instead remain trapped within cellular debris pyroptotic macrophages. trapping appears be an inevitable consequence how osmotic lysis ruptures and may also apply...
The protective antigen component of anthrax toxin forms a homoheptameric pore in the endosomal membrane, creating narrow passageway for enzymatic components to enter cytosol. We found that, during conversion heptameric precursor pore, seven phenylalanine-427 residues converged within lumen, generating radially symmetric heptad solvent-exposed aromatic rings. This “φ-clamp” structure was required protein translocation and comprised major conductance-blocking site hydrophobic drugs model...
Anthrax lethal toxin is a classical AB comprised of two components: protective antigen (PA) and factor (LF). Here, we show that following assembly endocytosis, PA forms channel translocates LF, not only into the cytosol, but also lumen endosomal intraluminal vesicles (ILVs). These ILVs can fuse release LF where proteolyze disable host targets. We find persist in for days, fully sheltered from proteolytic degradation, both vitro vivo. During this time, ILV-localized be transmitted to daughter...
The protective antigen (PA) moiety of anthrax toxin binds to cellular receptors and mediates entry the two enzymatic moieties into cytosol. Two PA receptors, receptor (ATR)/tumor endothelial marker 8 (TEM8) capillary morphogenesis protein 2 (CMG2), have been identified. We expressed purified von Willebrand A (VWA) domain CMG2 examined its interactions with monomeric heptameric forms PA. Monomeric bound a stoichiometric equivalent CMG2, whereas prepore form 7 eq. Kd VWA domain-PA interaction...
The effects of two supercharging reagents, m-nitrobenzyl alcohol (m-NBA) and sulfolane, on the charge-state distributions conformations myoglobin ions formed by electrospray ionization were investigated. Addition 0.4% m-NBA to aqueous ammonium acetate solutions results in an increase maximum charge state from 9+ 19+, average 7.9+ 11.7+, compared with without m-NBA. extent sulfolane a per mole basis is lower than that m-NBA, but comparable charging was obtained at higher concentration....
The effects of aqueous solution supercharging on the solution- and gas-phase structures two protein complexes were investigated using traveling-wave ion mobility-mass spectrometry (TWIMS-MS). Low initial concentrations m-nitrobenzyl alcohol (m-NBA) in electrospray ionization (ESI) can effectively increase charge concanavalin A dimers tetramers, but at higher m-NBA concentrations, increases are accompanied by solution-phase dissociation up to a ~22% collision cross section (CCS) tetramers....
Reported here is a laboratory in vitro evolution (LIVE) experiment based on an artificially expanded genetic information system (AEGIS). This delivers the first example of AEGIS aptamer that binds to isolated protein target, whose structural contact with its target has been outlined and inhibit biologically important activities protective antigen from Bacillus anthracis. We show how rational design secondary structure predictions can also direct use improve stability binding target. The...
Conflicting results exist regarding whether the folding of mammalian ubiquitin at 25 degrees C is a simple, two-state kinetic process or more complex, three-state with defined intermediate. We have measured rate constants up to about 1000 s(-1) using conventional rapid mixing methods in single-jump, double-jump, and continuous-flow modes. The linear dependence rates on denaturant concentration lack an unaccounted "burst-phase" change for fluorescence signal indicate that model adequate...
We compare the folding transition state (TS) of ubiquitin previously identified by using ψ analysis to that determined φ analysis. Both methods attempt identify interactions and their relative populations at rate-limiting step for folding. The TS ensemble derived from has an extensive native-like chain topology, with a four-stranded β-sheet network portion major helix. According analysis, however, is much smaller more polarized, only local helix/hairpin motif. find structured regions can...
Abstract Following assembly, the anthrax protective antigen (PA) forms an oligomeric translocon that unfolds and translocates either its lethal factor (LF) or edema (EF) into host cell. Here, we report cryo-EM structures of heptameric PA channels with partially unfolded LF EF at 4.6 3.1-Å resolution, respectively. The first α helix β strand unfold dock a deep amphipathic cleft, called clamp, which resides interface two monomers. α-clamp-helix interactions exhibit structural plasticity when...
A series of nonhydrolyzable ubiquitin dimer analogues has been synthesized and evaluated as inhibitors ubiquitin-dependent processes. Dimer were by cross-linking containing a terminal cysteine (G76C) to at position 11 ((76-11)Ub(2)), 29 ((76-29)Ub(2)), 48 ((76-48)Ub(2)), or 63 ((76-63)Ub(2)). head-to-head G76C ((76-76)Ub(2)) served control. These are mimics the different chain linkages observed in natural polyubiquitin chains. All showed weak inhibition toward catalytic domain UCH-L3 UBP...