Supramolecular Chemistry, Molecular Recognition, Nanoscience and Nanotechnology, Bioorganic Chemistry, Separations Chemistry, NMR Spectroscopy, Synthetic Ion Channels
Major Recognitions and Honors
Significant Professional Service and Activities
Phi Beta Kappa (1980); NIH Postdoctoral Fellow (1990-1993); Junior Faculty Award, College of Life Sciences, Univ. of Maryland (1997); Camille Dreyfus Teacher-Scholar Award (1998-2003);
UMCP Nanotechnology Advisory Board, 2004-present; Royal Society of Chemistry Inaugural Lecturer (2006);
Chair, 9th International Conference on Calixarene Chemistry (2007).
To date 30 undergraduates have done research with Prof. Davis. He has also mentored 12 Ph. D. degree recipients and 10 M. S. degree recipients.
DAVIS RESEARCH GROUP
SYNTHETIC ION CHANNELS, FUNCTIONAL NANOSTRUCTURES, SUPRAMOLECULAR CHEMISTRY
Our group is making molecular building blocks needed to form membrane-active structures via self-assembly. Our studies focus on the synthesis, characterization and use of synthetic channels for cations and anions and small molecules.
• Synthetic Na/K+ Channels-Potential Antibiotics. Cells have protein channels that facilitate rapid (106-108 ions/s) and selective transport of ions across plasma membranes. Nature’s important pores (K+ and Cl- channels) are formed by self-assembly in the bilayer membrane. We seek to mimic Nature’s strategy by making ion-transporting nanopores from the molecular self-assembly of small molecules. Such compounds are likely candidates for antibiotic activity. For example, we have prepared lipophilic guanosine nucleosides that form discrete supramolecular assemblies. Addition of K+ to these nucleosides triggers self-assembly to give nanoscale structures that are stable in non-polar environments (Fig. 1 and J. Am. Chem. Soc. 2011, 133, 19570-73)
With lipophilic exteriors and hydrophilic interiors these assemblies are ideal conduits for transporting ions across hydrophobic membranes. Indeed, we have found that a covalently modified guanosine assembly can transports K+ across phospholipid membranes. The next step, determining whether these structures form discrete channels in membranes, is being pursued in our labs. Once structure-function correlation studies are made for these membrane-active compounds, we will conduct bioassays to determine if these compounds demonstrate anti-bacterial or anti-fungal activity.
• Synthetic Cl – Channels. Anion transport across membranes is critical to life. Chloride channels regulate salt and fluid balance in cells. Dysfunction in chloride channels can lead to disease. Cystic fibrosis (CF) is caused by a defect in the protein that moves Cl- out of the cell. Small molecules that facilitate transmembrane transport of Cl- are attractive targets for therapeutic intervention. We have discovered a series of synthetic compounds that function in phospholipid membranes to transport Cl- anion across the bilayer.
Some of the compounds appear to function by a channel mechanism, whereas others seem to operate by a carrier mechanism. One goal is to accumulate solid electrophysiological and NMR data to demonstrate that these compounds selectively transport chloride anions by forming channels that span the membrane (see Chemical Communications, 2012, 48, 4432-34.)