Christy F Landes

Learn More
AMPA receptors mediate fast excitatory neurotransmission by converting chemical signals into electrical signals, and thus it is important to understand the relationship between their chemical biology and their function. We used single-molecule fluorescence resonance energy transfer to examine the conformations explored by the agonist-binding domain of the(More)
We find that citrate-stabilized gold nanoparticles aggregate and precipitate in saline solutions below the NaCl concentration of many bodily fluids and blood plasma. Our experiments indicate that this is due to complexation of the citrate anions with Na(+) cations in solution. A dramatically enhanced colloidal stability is achieved when bovine serum albumin(More)
We present in situ observations of adsorption of bovine serum albumin (BSA) on citrate-stabilized gold nanospheres. We implemented scattering correlation spectroscopy as a tool to quantify changes in the nanoparticle brownian motion resulting from BSA adsorption onto the nanoparticle surface. Protein binding was observed as an increase in the nanoparticle(More)
The superimposable dinucleotide fold domains of MetRS, GlnRS and TyrRS define structurally equivalent amino acids which have been used to constrain the sequence alignments of the 10 class I aminoacyl-tRNA synthetases (aaRS). The conservation of those residues which have been shown to be critical in some aaRS enables to predict their location and function in(More)
A method to denoise single-molecule fluorescence resonance energy (smFRET) trajectories using wavelet detail thresholding and Bayesian inference is presented. Bayesian methods are developed to identify fluorophore photoblinks in the time trajectories. Simulated data are used to quantify the improvement in static and dynamic data analysis. Application of the(More)
Fast excitatory synaptic signaling in the mammalian brain is mediated by AMPA-type ionotropic glutamate receptors. In neurons, AMPA receptors co-assemble with auxiliary proteins, such as stargazin, which can markedly alter receptor trafficking and gating. Here, we used luminescence resonance energy transfer measurements to map distances between the(More)
A hyperspectral imaging method was developed that allowed the identification of heterogeneous plasmon response from 50 nm diameter gold colloidal particles on a conducting substrate in a transparent three-electrode spectroelectrochemical cell under non-Faradaic conditions. At cathodic potentials, we identified three distinct behaviors from different(More)
Single-molecule fluorescence resonance energy transfer (SMFRET) was used to study the interaction of a 25-nucleotide (nt) DNA aptamer with its binding target, vascular endothelial growth factor (VEGF). Conformational dynamics of the aptamer were studied in the absence of VEGF in order to characterize fluctuations in the unbound nucleic acid. SMFRET(More)
The minus-strand transfer step of HIV-1 reverse transcription is chaperoned by the nucleocapsid protein (NC), which has been shown to facilitate the annealing between the transactivation response element (TAR) RNA and complementary TAR DNA stem-loop structures. In this work, potential intermediates in the mechanism of NC-chaperoned TAR DNA/TAR RNA annealing(More)
HIV-1 reverse transcription requires several nucleic acid rearrangement steps that are "chaperoned" by the nucleocapsid protein (NC), including minus-strand transfer, in which the DNA transactivation response element (TAR) is annealed to the complementary TAR RNA region of the viral genome. These various rearrangement processes occur in NC bound complexes(More)