A5055740405- Protein Structure and Dynamics
- Enzyme Structure and Function
- Clostridium difficile and Clostridium perfringens research
- RNA and protein synthesis mechanisms
- RNA modifications and cancer
- Antimicrobial Resistance in Staphylococcus
- Toxin Mechanisms and Immunotoxins
- Advanced NMR Techniques and Applications
- Computational Drug Discovery Methods
- RNA Research and Splicing
- Evolution and Genetic Dynamics
- Blood properties and coagulation
- Heat shock proteins research
- Monoclonal and Polyclonal Antibodies Research
- Photosynthetic Processes and Mechanisms
- Retinoids in leukemia and cellular processes
- Spectroscopy and Quantum Chemical Studies
- Organometallic Compounds Synthesis and Characterization
- Erythrocyte Function and Pathophysiology
- Autophagy in Disease and Therapy
- Viral gastroenteritis research and epidemiology
- Inorganic Chemistry and Materials
- Bacterial Genetics and Biotechnology
- Mitochondrial Function and Pathology
- Antioxidant Activity and Oxidative Stress
University of Maryland, Baltimore
2014-2024
Institute for Bioscience and Biotechnology Research
2016-2023
Advanced Bioscience Laboratories (United States)
2016-2023
University of Maryland Marlene and Stewart Greenebaum Comprehensive Cancer Center
2021
University of Maryland, College Park
2008-2020
National Institute of Standards and Technology
2020
University of Mary
2020
National High Magnetic Field Laboratory
2010
Florida State University
2010
Universidad de Granada
2004-2009
Vitamin A homeostasis is critical to normal cellular function. Retinol-binding protein (RBP) the sole specific carrier in bloodstream for hydrophobic retinol, main form which vitamin transported. The integral membrane receptor STRA6 mediates uptake of by recognizing RBP-retinol trigger release and internalization retinol. We present structure zebrafish determined 3.9-angstrom resolution single-particle cryo-electron microscopy. has one intramembrane nine transmembrane helices an intricate...
Local protein interactions ("molecular context" effects) dictate amino acid replacements and can be described in terms of site-specific, energetic preferences for any different acid. It has been recently debated whether these remain approximately constant during evolution or whether, due to coevolution sites, they change strongly. Such research highlights an unresolved fundamental issue with far-reaching implications phylogenetic analysis molecular modeling. Here, we take advantage the...
All ultrafast folding proteins known to date are either very small in size (less than 45 residues), have an α-helix bundle topology, or been artificially engineered. In fact, many of them share two even all three features. Here we show that gpW, a natural 62-residue α+β protein expected fold slowly two-state fashion, folds microseconds (i.e., from τ = 33 µs at 310 K 1.7 355 K). Thermodynamic analyses gpW reveal probe dependent thermal denaturation, complex coupling between denaturing agents,...
Differential scanning calorimetry was used to measure the temperature dependence of absolute heat capacity 35-residue subdomain villin headpiece, a protein that folds in 5 μs and is therefore assumed have small free-energy barrier separating folded unfolded states. To obtain an estimate height from calorimetric data, two models, variable-barrier model Ising-like model, were fit excess state over range 15−125 °C. The based on empirical mathematical form for density states, with four...
The importance and utility of Alaβ methyl groups as NMR probes molecular structure dynamics in high-molecular-weight proteins is explored. Using 2H 13C relaxation measurements {U-2H; Alaβ-[13CHD2]}-labeled Malate Synthase G (MSG)—an 82-kDa monomeric enzyme that contains 73 groups—we show the vast majority selectively labeled methyls are highly ordered. A number applications used for solution studies large protein molecules can benefit from proximity to backbone their high degree ordering. In...
Targeting Clostridium difficile infection is challenging because treatment options are limited, and high recurrence rates common. One reason for this that hypervirulent C. strains often have a binary toxin termed the toxin, in addition to enterotoxins TsdA TsdB. The has an enzymatic component, CDTa, pore-forming or delivery subunit CDTb. CDTb was characterized here using combination of single-particle cryoelectron microscopy, X-ray crystallography, NMR, other biophysical methods. In absence...
Abstract It is widely recognized that enhancement of protein stability an important biotechnological goal. However, some applications at least, could actually benefit from being strongly dependent on a suitable environment variable, in such way enhanced or decreased be realized as required. In therapeutic applications, for instance, long shelf‐life under storage conditions may convenient, but sufficiently fast degradation the after it has performed planned molecular task vivo avoid side...
Nuclear quadrupolar couplings are sensitive probes of hydrogen bonding. Experimental coupling constants α deuterons (Dα QCC) reported for the residues human ubiquitin that do not experience large-amplitude internal dynamics on pico- to nanosecond time scale. Two different methods Dα QCC estimation employed: (i) direct values from R1 and R2 2H rates using parameters (SCα−Hα2) derived 1 μs molecular simulations as well 13Cα relaxation measurements (ii) indirect via scalar second kind affects...
Flavodoxins are classified in two groups according to the presence or absence of a approximately 20-residue loop unknown function. In accompanying paper (36), we have shown that differentiating from long-chain Anabaena PCC 7119 flavodoxin is peripheral structural element can be removed without preventing proper folding apoprotein. Here investigate role played by stability and mechanism comparing equilibrium kinetic behavior full-length protein with loop-lacking, shortened variants. We show...
Molecular Dynamics simulations of the pentamidine-S100B complex, where two molecules pentamidine bind per monomer S100B, were performed in an effort to determine what properties would be desirable a pentamidine-derived compound as inhibitor for S100B. These predicted that increasing linker length allow single molecule span both binding sites on protein. The resulting compound, SBi4211 (also known heptamidine), was synthesized and experiments study its inhibition S100B performed. 1.65 Å X-ray...
Abstract We describe the design, kinetic properties, and structures of engineered subtilisin proteases that degrade active form RAS by cleaving a conserved sequence in switch 2. is signaling protein that, when mutated, drives third human cancers. To generate high specificity for target sequence, site was modified to be dependent on cofactor (imidazole or nitrite) protease sub-sites were create linkage between substrate binding. Selective proteolysis arises from 2-step process wherein...
Abstract Type 2 transglutaminase (TG2) functions as an important cancer cell survival protein in a range of cancers including epidermal squamous carcinoma. TG2 exists open and closed conformations each which has distinct mutually exclusive activity. The conformation GTP‐binding/GTPase activity while the transamidase to catalyze protein‐protein crosslinking. is required for maintenance aggressive phenotype. Thus, identifying agents that convert from inactive prevention/treatment strategy....
A recurrent theme of many structural studies homo-oligomeric protein systems is concerned with verification that the conformation observed in a crystal represents functionally relevant structure. An asymmetric adopted by two chemically identical subunits homo-oligomers can represent an intrinsic property or be artifact induced packing forces. Solution NMR distinguish between these possibilities. Using methyl-based spectroscopy, we provide evidence for symmetry absence ligands several...
Theory and experiments have shown that microsecond folding proteins exhibit characteristic thermodynamic properties reflect the limited cooperativity of over marginal barriers (downhill folding). Those studies mostly focused on with large α-helical contents small size, which tend to be fastest folders. A key open question is whether such are also present in all-β proteins. We address this issue by investigating unfolding thermodynamics a collection WW domains as representatives simplest...
NMR methodology is developed for high-resolution, accurate measurements of methyl 1Hm−13Cm (1DCH) and 13Cm−13C (1DCC) residual dipolar couplings (RDCs) in ILV-methyl-protonated high-molecular-weight proteins. Both types RDCs are measured a three-dimensional (3D) mode that allows dispersion correlations to the third (13Cβ/γ) dimension, alleviating problem overlap resonances highly complex methyl-abundant protein structures. The applied selectively ILV-protonated 82-kDa monomeric enzyme malate...