Over the last decade, the miniaturization of analytical systems has become an increasingly important and interesting research area. Miniaturized systems offer many advantages, including reduced reagent and sample consumption, shorter analysis times, portability and disposability. This dissertation describes novel approaches in this direction, focusing on two areas: the miniaturization of...
This thesis details my investigations of marine cyanobacterial natural products that resulted in the discovery of eighteen new secondary metabolites. Isolation and characterization of these unique molecules were carried out using different chromatographic techniques and by careful analyses of 1D and 2D NMR data, respectively. Preliminary bioassays of the crude...
Over the last decade, the use of highly branched macromolecules, called dendrimers, is emerging. Polyamidoamine (PAMAM) dendrimers, in particular, have attracted high interest due to their unique properties, such as well-defined size, shape, and solubility in water. Our group, as part of an interdisciplinary team, is currently working on developing...
Molecular genetic and enzymological techniques have been employed to study antibiotic biosynthesis. The nonproteinogenic amino acid capreomycidine is the signature residue found in the tuberactinomycin family of antitubercular peptide antibiotics and an important element of the pharmacophore. Recombinant VioG, a single module peptide synthetase from the viomycin gene cluster cloned...
Phospholipase C-β (PLC-β) isozymes are key effectors in G protein-coupled
signaling pathways. Prior research suggested that some isoforms of PLC-β may exist
and function as dimers, but little is known about dimerization of PLC-β. Data from coimmunoprecipitation
assays of differentially-tagged PLC-β constructs and sizeexclusion
chromatography of native PLC-β support homodimerization...
The concept of reducing laboratory operations in scale such that they fit on a microfluidic chip has been met with great enthusiasm. Lab-on-a-chip devices promise to be cost effective to operate due to reduced reagent consumption, have the potential to offer shorter analysis times due to their short path lengths,...
This research was undertaken to develop a sensitive, selective, and rapid analytical method to measure ethyl glucuronide (EtG) and ethyl sulfate (EtS) in urine as urinary biomarkers of alcohol exposure. Large-volume injection (LVI) coupled with liquid chromatography / electrospray tandem mass spectrometry was used to eliminate the need for either...
Met is a prognostic indicator of colorectal cancer patient survival. Therapies that target Met may therefore have beneficial outcomes in the clinic. Recently, EGCG was reported to suppress Met activation, although the mechanisms were not elucidated. HCT116 and HT29 human colon cancer cells were used to examine the relationships between...
Peroxiredoxins (Prxs) are dominant peroxide-reducing enzymes with two important roles: they protect all organisms from oxidative damage induced by peroxides, and in eukaryotes, they participate in hydrogen peroxide signaling pathways. This dissertation presents studies aimed at the biophysical characterization of select Prxs and a Prx reductase to elucidate their structure-function...
This research details laboratory assessment of bacterial hydrophobicity, variations in bacterial adhesion properties with growth and extended starvation as well as extension of this assay to colloidal hydrophobicity measurement. Hydrophobicity is an integral component of surface interactions and has been studied extensively for its role in a number of engineering...