Hydration differences between the major and minor grooves of DNA revealed from heat capacity measurements.

The nature of water on the surface of a macromolecule is reflected in the temperature dependence of the heat effect, i.e., the heat capacity change, ΔCp, that accompanies its removal on forming a complex.

Enthalpy-entropy compensation: the role of solvation.

Structural modifications to interacting systems frequently lead to changes in both the enthalpy (heat) and entropy of the process that compensate each other, so that the Gibbs free energy is little changed: a major barrier to the development of lead compounds in drug discovery. The conventional explanation for such enthalpy-entropy compensation (EEC) is that tighter contacts lead to a more negative enthalpy but increased molecular constraints, i.e.

Structural states of the flexible catalytic loop of M. tuberculosis tyrosyl-tRNA synthetase in different enzyme-substrate complexes.

Tyrosyl-tRNA synthetase from Mycobacterium tuberculosis (MtTyrRS) is an enzyme that belongs to class I of aminoacyl-tRNA synthetases, which catalyze the attachment of L-tyrosine to its cognate tRNATyr in the preribosomal step of protein synthesis. MtTyrRS is incapable of cross-recognition and aminoacylation of human cytoplasmic tRNATyr, so this enzyme may be a promising target for development of novel selective inhibitors as putative antituberculosis drugs. As a class I aminoacyl-tRNA synthetase, MtTyrRS contains the HIGH-like and KFGKS catalytic motifs that catalyze amino acid activation with ATP.

Experimental and theoretical study of the distance dependence of metal-enhanced fluorescence, phosphorescence and delayed fluorescence in a single system.

Distance dependent singlet and triplet metal-enhanced emission of eosin from silica coated silver island films (SiFs) has been studied by steady-state and time resolved fluorescence techniques, along with theoretical finite difference time domain (FDTD) numerical simulations, to understand how the thickness of the dielectric coating surrounding silver nanoparticles fundamentally affects luminescence enhancement. Our findings suggest that the distance dependence of metal-enhanced phenomena such as fluorescence, phosphorescence and delayed fluorescence is underpinned by the decay of the electric near-field, and depending on the actual silver silica sample embodiment, one can see either decreased or enhanced luminescence. These results not only expand our current MEF thinking but also suggest that one may well be able to approximate plasmon-enhanced luminescence values.

Sialyl residues modulate LPS-mediated signaling through the Toll-like receptor 4 complex.

We previously reported that neuraminidase (NA) pretreatment of human PBMCs markedly increased their cytokine response to lipopolysaccharide (LPS). To study the mechanisms by which this occurs, we transfected HEK293T cells with plasmids encoding TLR4, CD14, and MD2 (three components of the LPS receptor complex), as well as a NFκB luciferase reporting system. Both TLR4 and MD2 encoded by the plasmids are α-2,6 sialylated.

Ultra-fast pg/ml anthrax toxin (protective antigen) detection assay based on microwave-accelerated metal-enhanced fluorescence.

Rapid presymptomatic diagnosis of Bacillus anthracis at early stages of infection plays a crucial role in prompt medical intervention to prevent rapid disease progression and accumulation of lethal levels of toxin. To detect low levels of the anthrax protective antigen (PA) exotoxin in biological fluids, we have developed a metal-enhanced fluorescence (MEF)-PA assay using a combination of the MEF effect and microwave-accelerated PA protein surface absorption. The assay is based on a modified version of our "rapid catch and signal" (RCS) technology previously designed for the ultra-fast and sensitive analysis of genomic DNA sequences.

Two-color, 30 second microwave-accelerated Metal-Enhanced Fluorescence DNA assays: a new Rapid Catch and Signal (RCS) technology.

For analyses of DNA fragment sequences in solution we introduce a 2-color DNA assay, utilizing a combination of the Metal-Enhanced Fluorescence (MEF) effect and microwave-accelerated DNA hybridization. The assay is based on a new "Catch and Signal" technology, i.e.

Voltage-gated metal-enhanced fluorescence II: Effects of fluorophore concentration on the magnitude of the gated-current.

In this letter we report further findings on the ability of an applied direct current to modulate Metal-Enhanced Fluorescence (MEF). Fluorophores in close-proximity to just-continuous silver films (JCS) show significantly enhanced fluorescence intensities. However, when a current is applied to the films, the enhanced fluorescence can be gated in a manner that depends on both the fluorophore concentration, the magnitude of the applied current and the extent of the protein mono to multi-layer surface coverage.