Journal of the American Chemical Society

Solution Structure of a DNA Duplex Containing the Potent Anti-Poxvirus Agent Cidofovir

jbeadle — Wed, 30 Mar 2011 17:07:42 -0700

Cidofovir (1-(S)-[3-hydroxy-2-(phosphonomethoxy)propyl]cytosine, CDV) is a potent inhibitor of poxvirus replication. Prior studies have shown that the inhibition of replication involves effects of CDV incorporated into DNA on reactions catalyzed by both the 5?-to-3? polymerase and 3?-to-5? exonuclease activities of vaccinia virus DNA polymerase. However, the mechanism of inhibition of these DNA polymerase activities by the insertion of CDV into DNA remains unclear.

Journal of the American Chemical Society

Fast Characterization of Functionalized Silica Materials by Silicon-29 Surface-Enhanced NMR Spectroscopy Using Dynamic Nuclear Polarization

emsley — Thu, 24 Mar 2011 14:19:44 -0700

We demonstrate fast characterization of the distribution of surface bonding modes and interactions in a series of functionalized materials via surface-enhanced nuclear magnetic resonance spectroscopy using dynamic nuclear polarization (DNP). Surface-enhanced silicon-29 DNP NMR spectra were obtained by using incipient wetness impregnation of the sample with a solution containing a polarizing radical (TOTAPOL). We identify and compare the bonding topology of functional groups in materials obtained via a sol?gel process and in materials prepared by post-grafting reactions.

Journal of the American Chemical Society

Factors Governing the Na+ vs K+ Selectivity in Sodium Ion Channels

dmartinsen — Tue, 04 Jan 2011 10:36:11 -0800

Monovalent Na+ and K+ ion channels, specialized pore-forming proteins that play crucial biological roles such as controlling cardiac, skeletal, and smooth muscle contraction, are characterized by a remarkable metal selectivity, conducting the native cation while rejecting its monovalent contender and other ions present in the cellular/extracellular milieu. Compared to K+ channels, the principles governing Na+ vs K+ selectivity in both epithelial and voltage-gated Na+ channels are much less well understood due mainly to the lack of high-resolution 3D structures. Thus, many questions remain.