A5010024648- Biochemical and Molecular Research
- Enzyme Structure and Function
- Light effects on plants
- Photoreceptor and optogenetics research
- Protein Tyrosine Phosphatases
- Amino Acid Enzymes and Metabolism
- Cytomegalovirus and herpesvirus research
- Adenosine and Purinergic Signaling
- Photosynthetic Processes and Mechanisms
- Microfluidic and Capillary Electrophoresis Applications
- HIV/AIDS drug development and treatment
- Microfluidic and Bio-sensing Technologies
- Enzyme Production and Characterization
- Enzyme Catalysis and Immobilization
- bioluminescence and chemiluminescence research
- Porphyrin Metabolism and Disorders
- Proteins in Food Systems
- Glycosylation and Glycoproteins Research
- Signaling Pathways in Disease
- Protein Structure and Dynamics
- ATP Synthase and ATPases Research
- Microbial Metabolic Engineering and Bioproduction
- Polyamine Metabolism and Applications
- Sirtuins and Resveratrol in Medicine
- Cancer Research and Treatments
Hormel (United States)
2020-2025
University of Minnesota
2020-2025
Stony Brook University
2014-2024
State University of New York
2023
Pennsylvania State University
2012-2014
Corning (United States)
2013
Cornell University
2008-2011
Tri-Institutional PhD Program in Chemical Biology
2008-2010
Brock University
2003-2004
University of Maine
1987-1988
Significance We present a unique acoustic well approach that can precisely control cell-to-cell distance and cell–cell interactions. Our technology achieve high precision throughput simultaneously while preserving the integrity of cells. It is capable creating cell assemblies with precise spatial both in suspension on substrate. envision exploitation this powerful technology, for example, study interactions fields, such as immunology, developmental biology, neuroscience, cancer metastasis,...
Purine biosynthetic enzymes organize into dynamic cellular bodies called purinosomes. Little is known about the spatiotemporal control of these structures. Using super-resolution microscopy, we demonstrated that purinosomes colocalized with mitochondria, and results were supported by isolation purinosome mitochondria. Moreover, number purinosome-containing cells responded to dysregulation mitochondrial function metabolism. To explore role intracellular signaling, performed a kinome screen...
Significance We show that the assembly/disassembly of purinosome is cell cycle-dependent and correlates with cellular demands for purine biosynthesis encountered during cycle. The number purinosome-containing cells fluctuates: it peaks in G 1 phase HeLa cultured under purine-depleted conditions, but remains high across , S, 2 /M phases fibroblasts incapable salvage owing to a deficiency hypoxanthine-guanine phosphoribosyltransferase. Thus, function biomarker increased metabolic flux through...
Electrostatic interactions play an important role in enzyme catalysis by guiding ligand binding and facilitating chemical reactions. These electrostatic are modulated conformational changes occurring over the catalytic cycle. Herein, active site microenvironments examined for all complexes along cycle of Escherichia coli dihydrofolate reductase (ecDHFR) incorporation thiocyanate probes at two site-specific locations site. The electrostatics degree hydration surrounding investigated with...
Visualizing diverse anatomical and functional traits that span many spatial scales with high spatio-temporal resolution provides insights into the fundamentals of living organisms. Light-field microscopy (LFM) has recently emerged as a scanning-free, scalable method allows for high-speed, volumetric brain imaging. Given those promising applications at tissue level, its other extreme, this highly-scalable approach holds great potential observing structures dynamics in single-cell specimens....
Purine nucleotides are ubiquitous molecules that play vital roles in all kingdoms of life, not only as components nucleic acids, but also participating signaling and energy storage. Cellular pools purines maintained by the tight control several complementary sometimes competing processes including de novo biosynthesis, salvage catabolism nucleotides. While great strides have been made over past sixty years understanding biosynthesis purines, we experiencing a renaissance this field. In...
With the rapidly growing wealth of genomic data, experimental inquiries on functional significance important divergence sites in protein evolution are becoming more accessible. Here we trace dihydrofolate reductase (DHFR) and identify multiple key among 233 species between humans bacteria. We connect these sites, experimentally computationally, to changes enzyme’s binding properties catalytic efficiency. One identified evolutionarily is N23PP modification (∼mid-Devonian, 415–385 Mya), which...
The de novo biosynthesis of purines is carried out by a highly conserved metabolic pathway that includes several validated targets for anticancer, immunosuppressant, and anti-inflammatory chemotherapeutics. six enzymes in humans catalyze the 10 chemical steps from phosphoribosylpyrophosphate to inosine monophosphate were recently shown associate into dynamic multiprotein complex called purinosome. Here, we demonstrate heat shock protein 90 (Hsp90), 70 (Hsp70), cochaperones functionally...
The enzymes in the human de novo purine synthesis pathway were found to form a cellular complex, purinosome, upon culturing cells purine-depleted medium (An, S., Kumar R., Sheets, E. D., and Benkovic, S. J. (2008) Science 320, 103-106). Purinosome formation dissociation be modulated by several factors, including microtubule network cell signaling involving protein phosphorylation. To determine whether are physical contact, we probed for protein-protein interactions (PPIs) within purinosome...
Advances in modern X‐ray sources and detector technology have made it possible for crystallographers to collect usable data on crystals of only a few micrometers or less size. Despite these developments, sample handling techniques significantly lagged behind often prevent the full realization current beamline capabilities. In order address this shortcoming, surface acoustic wave‐based method manipulating patterning is developed. This method, which does not damage fragile protein crystals,...
Light-activated protein domains provide a convenient, modular, and genetically encodable sensor for optogenetics optobiology. Although these have now been deployed in numerous systems, the precise mechanism of photoactivation accompanying structural dynamics that modulate output domain activity remain to be fully elucidated. In C-terminal light–oxygen–voltage (LOV) plant phototropins (LOV2), blue light activation leads formation an adduct between conserved Cys residue embedded FMN...
Metabolic reprogramming of purine biosynthesis is a hallmark cancer metabolism and represents critical vulnerability. The enzyme phosphoribosylformylglycinamidine synthase (PFAS) catalyzes the fourth step in de novo has been demonstrated to be prognostic for survival liver cancer. Despite importance this protein as drug target, there are no known specific inhibitors PFAS activity. Here, we describe new continuous, spectrophotometric assay domain that amenable high-throughput screening (HTS)....
Recent developments on various lab-on-a-chip techniques allow miniaturized and integrated devices to perform on-chip single-molecule studies. Fluidic-based platforms that utilize unique microscale fluidic behavior are capable of conducting experiments with high sensitivities throughputs, while biomolecular systems can be studied using such as DNA curtains, magnetic tweezers, solid-state nanopores. The advances these lead next-generation devices, transistors, real-time (SMRT) technology for...
Eliciting a cellular response to changing chemical microenvironment is central many biological processes including gene expression, cell migration, differentiation, apoptosis, and intercellular signaling. The nature scope of the highly dependent upon spatiotemporal characteristics stimulus. To date, studies that investigate this phenomenon have been limited digital (or step) stimulation with little control over temporal counterparts. Here, we demonstrate an acoustofluidic (i.e., fusion...
The flavin chromophore in blue-light-using FAD (BLUF) photoreceptors is surrounded by a hydrogen bond network that senses and responds to changes the electronic structure of on ultrafast time scale. includes strictly conserved Tyr residue, previously we explored role this Y21, photoactivation mechanism BLUF protein AppABLUF introduction fluorotyrosine (F-Tyr) analogues modulated pKa reduction potential Y21 3.5 pH units 200 mV, respectively. Although little impact forward (dark- light-adapted...
The rational engineering of photosensor proteins underpins the field optogenetics, in which light is used for spatiotemporal control cell signaling. Optogenetic elements function by converting electronic excitation an embedded chromophore into structural changes on microseconds to seconds time scale, then modulate activity output domains responsible biological Using time-resolved vibrational spectroscopy coupled with isotope labeling, we have mapped evolution LOV2 domain flavin binding...
Phospholipid extrusion by ABC subfamily A (ABCA) exporters is central to cellular physiology, although the specifics of underlying substrate interactions and transport mechanisms remain poorly resolved at molecular level. Here we report cryo-EM structures lipid-embedded human ABCA7 in an open state a nucleotide-bound, closed resolutions between 3.6 4.0 Å. The former reveals ordered patch bilayer lipids traversing transmembrane domain (TMD), while latter lipid-free, TMD with small...
Nicotinamidases are metabolic enzymes that hydrolyze nicotinamide to nicotinic acid. These widely distributed across biology, with examples found encoded in the genomes of Mycobacteria, Archaea, Eubacteria, Protozoa, yeast, and invertebrates, but there none mammals. Although recent structural work has improved our understanding these enzymes, their catalytic mechanism is still not well understood. Recent data show nicotinamidases required for growth virulence several pathogenic microbes. The...
The final two steps of de novo uridine 5'-monophosphate (UMP) biosynthesis are catalyzed by orotate phosphoribosyltransferase (OPRT) and orotidine decarboxylase (OMPDC). In most prokaryotes simple eukaryotes these enzymes encoded separate genes, whereas in mammals they expressed as a bifunctional gene product called UMP synthase (UMPS), with OPRT at the N terminus OMPDC C terminus. Leishmania some closely related organisms also express enzyme for steps, but domain order is reversed relative...