Microfluidic devices for electrokinetic sample fractionation.

We present three generations of microchip-based "in-space" sample fractionators and collectors for use in proteomics. The basic chip design consisted of a single channel for CE separation of analytes that then intersects a fractionation zone feed into multiple high aspect ratio microchannels for fractionation of separated components. Achievements of each generation are discussed in relation to important design criteria.

Electronic energy changes associated with Guanine quadruplex formation: an investigation at the atomic level.

Guanine quadruplexes have received a lot of attention due to their possible role as therapeutic agents. Specifically, it is the ability of these quadruplex structures to inhibit telomerase, an enzyme found to be highly active in a large percentage of tumor cells and thought to confer immortality upon these cells. However, although a great deal of research has focused on enhancing the formation of these structures and their anticancer activity, many questions remain about the quadruplex structures themselves.

Validation of all-atom phosphatidylcholine lipid force fields in the tensionless NPT ensemble.

A recently defined charge set, to be used in conjunction with the all-atom CHARMM27r force field, has been validated for a series of phosphatidylcholine lipids. The work of Sonne et al. successfully replicated experimental bulk membrane behaviour for dipalmitoylphosphatidylcholine (DPPC) under the isothermal-isobaric (NPT) ensemble.

Classification of water molecules in protein binding sites.

Water molecules play a crucial role in mediating the interaction between a ligand and a macromolecular receptor. An understanding of the nature and role of each water molecule in the active site of a protein could greatly increase the efficiency of rational drug design approaches: if the propensity of a water molecule for displacement can be determined, then synthetic effort may be most profitably applied to the design of specific ligands with the displacement of this water molecule in mind. In this paper, a thermodynamic analysis of water molecules in the binding sites of six proteins, each complexed with a number of inhibitors, is presented.

A glassy carbon microfluidic device for electrospray mass spectrometry.

Due to the broad impact of microfabrication technology on chemistry and biology, new methods to pattern and etch a variety of materials are being explored in a number of laboratories. Here, we report the design, fabrication, and operation of a glassy carbon (GC) microchip interfaced to a nanoelectrospray ionization source and a quadrupole mass spectrometer. The method involves standard photolithographic pattern transfer to a photoresist layer and anodization of the exposed GC substrate in basic electrolyte to produce a series of channels with well-defined wall structure.