Positively charged counterions drive RNA molecules into compact configurations that lead to their biologically active structures. To understand how the valence and size of the cations influences the collapse transition in RNA, small-angle X-ray scattering was used to follow the decrease in the radius of gyration (R(g)) of the Azoarcus and Tetrahymena ribozymes in different cations. Small, multi...

In this thesis, we investigate a variety of problems involving the interaction of cationic peptides with lipid membranes. To this end we adopt Poisson-Boltzmann (PB) theory and coarse-grained models of these molecules. We first examine the electrostatic interaction of a positively-charged peptide with a negatively charged membrane immersed in a salty solution. In particular, we study how this i...

We have investigated the electric conductivity, dielectric relaxation behavior, and viscosity for the aqueous solution of cyanobacterial megamolecules, molecular weight =1.6×10(7) g/mol, named sacran. Sacran is an anionic polyelectrolyte which has carboxylate and sulfate groups on the saccharide chain. The electric conductivity and the zero shear viscosity demonstrated three crossover concentra...

A new technique for Monte Carlo sampling of the hard-sphere collision force has been applied to study the interaction between a pair of spherical macroions in primitive-model electrolyte solutions with valences 1:2, 2:1, and 2:2. Macroions of the same charge can attract each other in the presence of divalent counterions, in analogy with earlier observations for planar and cylindrical geometries...

Discrete aqueous metal oxide polyionic clusters that include aluminum polycations, transition-metal polyoxometalates, and the actinyl peroxide clusters have captivated the interest of scientists in the realm of both their fundamental and applied chemistries. Yet the counterions for these polycations or polyanions are often ignored, even though they are imperative for solubility, crystallization...

The present communication deals with the local anesthetic activity and toxicity of 16 basic alkyl esters of substituted pyrrolidine dicarboxylic acids.t In an accompanying article5 the intestinal, uterine, and depressor activity of these compounds is presented. Twelve of the compounds were 2, 5-di-(3-diethylaminoethyl) esters and 3 were 2, 5-di-(y-diethylaminopropyl) esters. One was 2-(Zdiethyl...

Yersinia pestis, the causative agent of plague, poses a serious health threat to rodents and human beings. TyrR is a transcriptional regulator (TyrR) that controls the metabolism of aromatic amino acids in Escherichia coli. In this paper, TyrR played an important role in Y. pestis virulence. Inactivation of tyrR did not seem to affect the in vitro growth of this organism, but resulted in at lea...