Evaluation of Martian soil analog materials. Development of new methods for direct monitoring of pollutants via mass spectrometry. Novel analytical techniques for separation and detection of redox-sensitive trace species. Determination of structures and speciation of metals and trace elements adsorbed on environmental surfaces. Modeling speciation, precipitation and adsorption reactions of trace elements in environmental systems. Mechanisms of heavy metal tolerance/accumulation in plants. Effects of heavy metals on gene expression in plants. Detection of trace levels of volatile organic compounds and heavy metals in urban air, water and soil samples. Investigation of the cycling of non-living organic matter in aquatic systems in the context of the oceanic and global carbon cycles.
Enzyme reaction mechanisms. Synthesis of enzyme inhibitors, characterization of transition-state analogs and measurement of enzyme-ligand interactions. Isolation and characterization of methyl transferase enzymes. Structure-function relationships in membrane transport proteins and mechanisms of membrane biogenesis, with emphasis on outer membrane proteins of Escherichia coli. Biosynthesis and regulation of the expression of complex carbohydrate cell surface antigens. Characterization of enzymes involved in the nitric oxide cellular signaling pathway. Structural and functional studies of metalloproteins involved in redox reactions, oxygen activation, oxygen transport and signal transduction.
Reaction mechanisms and synthetic applications of organic peroxides. Small rings. Heterocyclic chemistry. Chemistry of singlet oxygen. Mechanisms of fundamental organic reactions: computational approaches to modeling the transition states of nucleophilic substitutions and elimination reactions. Conformations of small peptides. Structure-reactivity relationships in acid- and base-catalyzed organic reactions, including heterolytic cleavage of C-H and C-C bonds. Design and synthesis of substrate analogs to elucidate the catalytic mechanisms of enzymes. Design and synthesis of novel enzyme inhibitors for use in sensitizing tumor cells to common chemotherapeutic strategies.
Characterization of structural features and dynamic behavior of natural and synthetic macromolecules in solution using physical methods and theoretical models. High precision computational modeling and electro-optic characterization of hydrodynamic transport properties of small, medium, and large molecules. Electrical and mechanical properties of nucleic acids, proteins, molecular motors, and protein-nucleic acid complexes. Biophysical applications of electron spin resonance spin labels. Diffusion and solubility of molecular oxygen in biomembranes and in other tissue. Biophysical spectroscopic methods, including nanosecond time-resolved polarized absorption spectroscopy, to characterize biological function and examine the molecular basis of disease.