A5067672382- Mass Spectrometry Techniques and Applications
- Enzyme Structure and Function
- Analytical Chemistry and Chromatography
- Biochemical and Molecular Research
- RNA and protein synthesis mechanisms
- Bacterial Genetics and Biotechnology
- ATP Synthase and ATPases Research
- Protein Structure and Dynamics
- Mitochondrial Function and Pathology
- Metabolomics and Mass Spectrometry Studies
- Ubiquitin and proteasome pathways
- Infrastructure Maintenance and Monitoring
- Endoplasmic Reticulum Stress and Disease
- Asphalt Pavement Performance Evaluation
- Ion-surface interactions and analysis
- Innovative concrete reinforcement materials
- Impact of Light on Environment and Health
- Safety Warnings and Signage
- Redox biology and oxidative stress
- Analytical chemistry methods development
- Microplastics and Plastic Pollution
- Protein Hydrolysis and Bioactive Peptides
- Cellular transport and secretion
- Polymer crystallization and properties
- Advanced Proteomics Techniques and Applications
University of Guelph
2021-2025
Hospital for Sick Children
2018-2020
University of Toronto
2018-2020
SickKids Foundation
2019
Drexel University
2018-2019
Great Ormond Street Hospital
2019
University College London
2019
Western University
2012-2018
University of Massachusetts Boston
2013
University of Massachusetts Dartmouth
2013
Electrospray ionization (ESI) generates intact gas-phase ions from analytes in solution for mass spectrometric investigations. ESI can proceed via different mechanisms. Low molecular weight follow the ion evaporation model (IEM), whereas charged residue (CRM) applies to large globular species. A chain ejection (CEM) has been proposed disordered polymers.
The objective of this study was to examine if asphalt rejuvenators can offset the stiffness attributed by hardened binder from reclaimed pavement (RAP) and shingles (RAS) in mixtures that incorporate high RAP RAS content without adverse impact on performance mixtures. Also, assess, help RAP/RAS comingle with virgin binder. Overall, results showed mitigate resultant cracking characteristics mixture improved addition rejuvenators, however, rutting moisture susceptibility were adversely...
The ClpXP degradation machine consists of a hexameric AAA+ unfoldase (ClpX) and pair heptameric serine protease rings (ClpP) that unfold, translocate, subsequently degrade client proteins. is an important target for drug development against infectious diseases. Although structures are available isolated ClpX ClpP rings, it remains unknown how symmetry mismatched work in tandem processive substrate translocation into the proteolytic chamber. Here, we present cryo-EM substrate-bound complex...
Many protein investigations by electrospray ionization (ESI) mass spectrometry (MS) strive to ensure a "native" solvent environment, i.e., nondenaturing conditions up the point of gas-phase ion formation. Ideally, these studies would employ volatile pH buffer mitigate changes in H(+) concentration that can occur during ESI. Ammonium acetate is commonly used additive, despite its low buffering capacity at 7. bicarbonate provides greatly improved stabilization, thus offering an interesting...
Significance ClpP is a protease that degrades damaged or misfolded proteins. Consistent with its critical role in maintaining cellular homeostasis, inhibiting and dysregulating function has shown promise fighting antibiotic resistance targeting cancer cells acute myeloid leukemia. Here we identify conformational switch that, upon mutagenesis, leads to catalytically inactive structure can be reactivated through the binding of small-molecule activators. This functional hotspot therefore...
The 300-kDa ClpP1P2 protease from Mycobacterium tuberculosis collaborates with the AAA+ (ATPases associated a variety of cellular activities) unfoldases, ClpC1 and ClpX, to degrade substrate proteins. Unlike in other bacteria, all components Clp system are essential for growth virulence mycobacteria, their inhibitors show promise as antibiotics. MtClpP1P2 is unique that it contains pair distinct ClpP1 ClpP2 rings also requires presence activator peptides, such benzoyl-leucyl-leucine (Bz-LL),...
The question whether electrosprayed protein ions retain solution-like conformations continues to be a matter of debate. One way address this issue involves comparisons collision cross sections (Ω) measured by ion mobility spectrometry (IMS) with Ω values calculated for candidate structures. Many investigations in area employ traveling wave IMS (TWIMS). It is often implied that nanoESI more conducive the retention solution structure than regular ESI. Focusing on ubiquitin, cytochrome c,...
Oxidative phosphorylation, the combined activity of electron transport chain (ETC) and adenosine triphosphate synthase, has emerged as a valuable target for treatment infection by Mycobacterium tuberculosis other mycobacteria. The mycobacterial ETC is highly branched with multiple dehydrogenases transferring electrons to membrane-bound pool menaquinone oxidases from pool. proton-pumping type I nicotinamide adenine dinucleotide (NADH) dehydrogenase (Complex I) found in low abundance plasma...
The coupling of electrospray ionization (ESI) with ion mobility-mass spectrometry (IM-MS) allows structural studies on biological macromolecules in a solvent-free environment. Collision cross sections (CCSs) measured by IM-MS provide measure analyte size. For native proteins and their complexes, many features can be preserved the gas phase, making powerful approach for range bioanalytical applications. In addition to tightly folded conformers, large number partially disordered participate...
Kinetic measurements can provide insights into protein folding mechanisms. However, the initial (submillisecond) stages of still represent a formidable analytical challenge. A number ultrarapid triggering techniques have been available for some time, but coupling these with detection methods that are capable providing detailed structural information has proven to be difficult. The current work addresses this issue by combining submillisecond mixing laser-induced oxidative labeling....
Hydroxyl radical (⋅OH) labeling with mass spectrometry detection reports on protein conformations and interactions. Fast photochemical oxidation of proteins (FPOP) involves ⋅OH production via H2O2 photolysis by UV laser pulses inside a flow tube. The experiments are conducted in the presence scavenger (usually glutamine) that shortens lifetime. literature claims FPOP takes place within 1 μs. This ultrafast time scale implies should be immune to labeling-induced artifacts may encountered...
Mass spectrometry (MS)-based protein conformational studies are a rapidly growing field. The characterization of partially disordered conformers is particular interest because these species not amenable to classical high-resolution techniques. Such equilibrium intermediates can often be populated by exposure mildly acidic pH. Hydroxyl radical (·OH) introduces oxidative modifications at solvent-accessible side chains, while buried sites protected. ·OH generated laser photolysis H(2)O(2) (fast...
Significance F O 1 , or ATP synthase, is often referred to as the “world’s smallest motor.” Similar automotive engines, it employs a rotating shaft that interacts with mechanical actuators. When operating combustion engine under load, bearings exert significant forces on crankshaft, leading enhanced stress. Here, we demonstrate analogous load-dependent effects occur in molecular motors. pumps protons against transmembrane gradient, rotor undergoes structural destabilization attributed...
The mechanisms whereby protein ions are liberated from charged droplets during electrospray ionization (ESI) remain under investigation. Compact conformers electrosprayed aqueous solution in positive ion mode likely follow the residue model (CRM), which envisions analyte release after solvent evaporation to dryness. concentration of nonvolatile salts such as NaCl increases sharply within vanishing CRM droplets, promoting nonspecific pairing Cl(-) and Na(+) with groups on surface. For...
Energy conversion by electron transport chains occurs through the sequential transfer of electrons between protein complexes and intermediate carriers, creating proton motive force that enables ATP synthesis membrane transport. These can also form higher order assemblies known as respiratory supercomplexes (SCs). The chain opportunistic pathogen Pseudomonas aeruginosa is closely linked with its ability to invade host tissue, tolerate harsh conditions, resist antibiotics but poorly...
The Pup-proteasome system (PPS) is a unique bacterial proteolytic pathway found in some species, including Mycobacterium tuberculosis, that plays vital role maintaining proteome integrity and survival during infection. Pupylation the process of tagging substrates with Pup for degradation catalyzed by PafA, sole ligase bacteria. However, how PafA interacts diverse targets its oligomeric state remain poorly understood. Although X-ray crystal structures have characterized as domain-swapped...
Royal jelly (RJ) triggers the development of female honeybee larvae into queens. This effect has been attributed to presence major royal protein 1 (MRJP1) in RJ. MRJP1 isolated from is tightly associated with apisimin, a 54-residue α-helical peptide that promotes noncovalent assembly multimers. No high-resolution structural data are available for these complexes, and their binding stoichiometry remains uncertain. We examined MRJP1/apisimin using range biophysical techniques. also...
Abstract Bacterial ClpP is a highly conserved, cylindrical, self-compartmentalizing serine protease required for maintaining cellular proteostasis. Small molecule acyldepsipeptides (ADEPs) and activators of self-compartmentalized proteases 1 (ACP1s) cause dysregulation activation ClpP, leading to bacterial cell death, highlighting their potential use as novel antibiotics. Structural changes in Neisseria meningitidis Escherichia coli upon binding ACP1 ADEP analogs were probed by X-ray...
Intracellular protein degradation is vital across all domains of life 1 . In eukaryotes, the ubiquitin proteasome system performs most non-lysosomal and influences numerous cellular processes. Some bacteria, including human pathogen Mycobacterium tuberculosis ( Mtb ), encode a that selectively degrades damaged or misfolded proteins crucial for pathogen’s survival within host macrophages 2–7 Consequently, 20S core particle (CP), central component system, has emerged as viable target treatment...
ClpXP is a two-component mitochondrial matrix protease. The caseinolytic peptidase chaperone subunit X (ClpX) recognizes and translocates protein substrates into the degradation chamber of protease P (ClpP) for proteolysis. degrades damaged respiratory chain proteins necessary cancer cell survival. Despite critical role in quality control, specific degrons, or modifications that tag substrate by human ClpXP, are still unknown. We demonstrated phosphorylated serine (pSer) targets to ClpX...
Abstract Mitochondrial proteostasis is essential to maintain cellular function and survival. YME1L protease an important contributor which belongs the AAA+ ( A TPases ssociated with diverse ctivities) family anchored inner mitochondrial membrane. plays a pivotal role in protein quality control by selectively degrading misfolded native proteins. The precise mechanisms nucleotide binding hydrolysis influence YME1L’s conformational dynamics, proteolytic activity, stability remain unclear. Here...
Human ClpP protease contributes to mitochondrial protein quality control by degrading misfolded proteins. is overexpressed in cancers such as acute myeloid leukemia (AML), where its inhibition leads the accumulation of damaged respiratory chain subunits and cell death. Conversely, hyperactivating with small-molecule activators, recently discovered ONC201, disrupts degradation impairs respiration cancer cells. Despite critical role human health, mechanism underlying structural functional...