A5031847066- Protein Structure and Dynamics
- Force Microscopy Techniques and Applications
- Computational Drug Discovery Methods
- Receptor Mechanisms and Signaling
- Protein Kinase Regulation and GTPase Signaling
- Enzyme Structure and Function
- Microtubule and mitosis dynamics
- Chemical Synthesis and Analysis
- Photosynthetic Processes and Mechanisms
- Mosquito-borne diseases and control
- Viral Infections and Vectors
- Monoclonal and Polyclonal Antibodies Research
- Nanofabrication and Lithography Techniques
- Advanced Electron Microscopy Techniques and Applications
- RNA and protein synthesis mechanisms
- Advanced Fluorescence Microscopy Techniques
- Cancer therapeutics and mechanisms
- Bacterial Genetics and Biotechnology
- Insect symbiosis and bacterial influences
- Tuberculosis Research and Epidemiology
- ATP Synthase and ATPases Research
- thermodynamics and calorimetric analyses
- Orbital Angular Momentum in Optics
- Adhesion, Friction, and Surface Interactions
- Biochemical and Structural Characterization
Georgetown University
2016-2025
QB3
2011-2014
The University of Texas Medical Branch at Galveston
2004-2014
University of California, Berkeley
2011-2013
Bergen Kommune
2012
Galveston College
2007
Understanding the mechanisms of allosteric regulation in response to second messengers is crucial for advancing basic and applied research. This study focuses on differential by ubiquitous signaling molecule, cAMP, cAMP receptor protein from Escherichia coli (CRPEcoli) Mycobacterium tuberculosis (CRPMTB). By introducing structurally homologous mutations hotspots previously identified CRPEcoli into CRPMTB examining their effects solution structure, stability function, we aimed determine...
Protein kinase A (PKA) is a crucial signaling enzyme in neurons, with its dysregulation being implicated neurodegenerative diseases. Assembly of the PKA holoenzyme, comprising dimer heterodimers regulatory (R) and catalytic (C) subunits, ensures allosteric regulation functional specificity. Recently, we defined RIβ-L50R variant as causative mutation that triggers protein aggregation rare disease, neuronal loss, parkinsonism driven by (NLPD-PKA). However, mechanism underlying uncontrolled...
Abstract Optical tweezers has emerged as a powerful tool to study folding, ligand binding, and motor enzymes. The manipulation of proteins with optical requires attaching molecular handles the protein interest. Here, we describe novel method that integrates covalent attachment DNA target selection step for functional properly folded molecules. In addition, this enables obtaining molecules in different liganded states can be used lengths. We apply cAMP binding domain A (CBD-A) Protein kinase...
Cyclic nucleotide-binding (CNB) domains allosterically regulate the activity of proteins with diverse functions, but mechanisms that enable cyclic signal to distant are not well understood. Here we use optical tweezers and molecular dynamics dissect changes in folding energy landscape associated cAMP-binding signals transduced between two CNB protein kinase A (PKA). We find response upon cAMP binding is domain specific, resulting unique mutually coordinated tasks: one initiates...
Abstract Knots are remarkable topological features in nature. The presence of knots crystallographic structures proteins have stimulated considerable research to determine the kinetic and thermodynamic consequences threading a polypeptide chain. By mechanically manipulating MJ0366, small single domain protein harboring shallow trefoil knot, we allow refold from either knotted or unknotted denatured state characterize free energy profile associated both folding pathways. comparing stability...
The link between cofactor binding and protein activity is well-established. However, how interactions modulate folding of large proteins remains unknown. We use optical tweezers, clustering global fitting to dissect the mechanism Drosophila cryptochrome (dCRY), a 542-residue that binds FAD, one most chemically structurally complex cofactors in nature. show first dCRY parts fold are independent but later steps FAD-driven as remaining polypeptide folds around cofactor. FAD largely unfolded...
Significance Mutations, deletions, or gene fusions in protein kinases have been associated with the development of many diseases humans and led to emergence kinase family as an important therapeutic drug target. In cell, activity is often turned on off allosterically by intramolecular regulatory domains, flexible linkers, other interacting proteins. Here, we use single-molecule optical tweezers investigate mechanism allosteric regulation cAMP-dependent PKA. This approach allowed us determine...
Allosteric proteins with multiple subunits and ligand-binding sites are central in regulating biological signals. The cAMP receptor protein from Mycobacterium tuberculosis (CRPMTB) is a global regulator of transcription composed two identical subunits, each one harboring structurally conserved cAMP- DNA-binding sites. mechanisms by which these four binding allosterically coupled CRPMTB remain unclear. Here, we investigate the mechanism between cAMP, linkage DNA interactions. Using...
Global conformational and oligomeric states of the Escherichia coli replicative factor DnaC protein in absence presence magnesium nucleotide cofactors, ATP ADP, their fluorescent analogues, MANT-ATP MANT-ADP, have been examined using analytical sedimentation velocity time-dependent fluorescence anisotropy techniques. In solution, exists exclusively as a monomer over large concentration range. The value = 2.45 ± 0.07 S indicates that molecule has an elongated shape. When modeled prolate...
The envelope protein domain III (ED3) of West Nile virus is the major virus-specific neutralization and harbors most critical mutations that induce resistance against antibody-mediated neutralization. We investigated molecular mechanisms by studying biophysical perturbations monoclonal antibody (mAb)-resistant on ED3 wild type. Our results showed although solution structure between type mutants was preserved, confer highest degree to mAbs low stability high local dynamic motions....
Mutations in the epitopes of antigenic proteins can confer viral resistance to antibody-mediated neutralization. However, fundamental properties that characterize epitope residues and how mutations affect antibody binding alter virus susceptibility neutralization remain largely unknown. To address these questions, we used an ensemble-based algorithm effects on thermodynamics protein conformational fluctuations. We applied this method envelope domain III (ED3) two medically important...
Abstract Protein kinase A (PKA) is a crucial signaling enzyme in neurons, with its dysregulation being implicated neurodegenerative diseases. Assembly of the PKA holoenzyme, comprising dimer heterodimers regulatory (R) and catalytic (C) subunits, ensures allosteric regulation functional specificity. Recently, we defined RIβ-L50R variant as causative mutation that triggers protein aggregation rare disease. However, mechanism underlying uncontrolled connection to outcomes leading clinical...
Cyclic-nucleotide binding (CNB) domains are structurally and evolutionarily conserved signaling modules that regulate proteins with diverse folds functions. Despite a wealth of structural information, the mechanisms by which CNB couple cyclic-nucleotide to conformational changes involved in signal transduction remain unknown. Here we combined single-molecule computational approaches investigate conformation folding energetics two regulatory subunit protein kinase A (PKA). We found exhibit...
A bstract Cyclic nucleotide binding (CNB) domains are universally conserved signaling modules that regulate the activities of diverse protein functions. Yet, structural and dynamic features enable cyclic signal to allosterically other functional remain unknown. We use force spectroscopy molecular dynamics monitor in real time pathways signals transduced by cAMP kinase (PKA). Despite being structurally conserved, we find response folding energy landscape is domain-specific, resulting unique...