CHEMISTRY

Andrew Lantz: My current research interests focus on applying analytical separation techniques, primarily capillary electrophoresis, to the analysis of biologically active molecules and biocolloids. Capillary electrophoresis is a rapid technique traditionally used for the separation of molecules by their size-to-charge ratio by an applied electric field. One aspect of our research is to develop methods to use this technique for the separation and analysis of live microorganisms (i.e. bacteria and unicellular fungi) by exploiting their differences in shape and surface charge. Other areas of research involve equilibrium and partitioning studies to measure binding constants and other interaction parameters between molecules, and enantioseparations of pharmaceuticals and other optically active compounds.

Blair Miller: As an analytical separations chemist, my current interests are in the area of developing separation methodologies for real world samples such as active components in pharmaceutical formulations. Currently, most of my work is in reversed-phase liquid chromatography, but I am looking to expand the separation work into gas chromatography and capillary electrophoresis.

Min Qi: The projects in my lab focus on environmental analytical chemistry. In particular I am interested in: (1) the analysis of toxic organic compounds (including PCBs, DDE, and PAHs), in water, sediment, and fish using GC-ECD and GC-MS; (2) studying the neurotoxicity and kinetics of PCB congeners on gold fish in collaboration with the faculty in the psychology department; and (3) the analysis of heavy metals and ions in waste water and ground water using Atomic Absorption (AA) and Ion Chromatography (IC).

 

BIOCHEMISTRY

Mary Karpen: My research is in the area of computational biochemistry, with a focus on RNA and peptide molecular dynamics and free energy simulations. Results from the Human Genome Project have indicated RNA structures are of crucial importance in gene regulation. One method of studying these structures is via computer simulations. The goal of our research is to identify reliable simulation techniques for RNA structures. Another focus of our group is to develop computer animations for science education. An example of some of our animations can be found at http://faculty.gvsu.edu/karpenm/melissa/mainindex.html.

David Leonard: The main projects in our lab center on structure/function studies of beta-lactamases, the family of enzymes that are responsible for bacterial resistance to penicillin and cephalosporin-type beta-lactam antibiotics. Currently, we are studying the mechanism of substrate and inhibitor specificity in the Class D enzyme OXA-1. Our current approach is to synthesize, express and purify mutant forms of OXA-1, and then test the altered enzymes by kinetic assay.

Rachel Powers: b-lactamases are the leading cause of resistance to b-lactam antibiotics, to which penicillins and cephalosporins belong. These enzymes hydrolyze the defining lactam ring of the antibiotic, rendering the antibiotic ineffective. One way to overcome resistance would be block the activity of these enzymes. Several inhibitors of b-lactamase are available clinically, however these inhibitors also contain a lactam ring. Therefore resistance develops rapidly to these chemically similar inhibitors, as well. The long-term goal of my lab is to use a structure-based drug design approach to design novel inhibitors for the class C b-lactamase AmpC.

Brad Wallar: Our lab is interested in the proteins involved in intracellular signaling networks that regulate cellular proliferation, shape, and motility. Specifically, we study the Diaphanous-related Formins, a highly conserved family of proteins that act as regulators of the cellular "skeleton." We employ a combination of biochemical (protein purification, fluorescence spectroscopy) and molecular/cell biological techniques (various subcloning techniques, mutagenesis, cellular microinjection) to define specific protein-protein interactions that regulate the function of these proteins. The tight regulation of these proteins is vital, as uncontrolled activation of them can result in dire consequences for a cell, such as cancer.

 

INORGANIC CHEMISTRY

John Bender: In my research group we are interested in the synthesis and characterization of main group organometallics. We are specifically interested in the synthesis of derivatives of ortho-benzotrifluoroaryls and the characterization of these molecules using heteronuclear NMR.

Steve Matchett: Research in our lab centers on the organometallic chemistry (a field combining organic and inorganic chemistry) of Carbon-Carbon double bonds. Compounds containing Carbon-Carbon double bonds are also known as olefins. Our work seeks to address the relationship between the way in which transition metals bond to olefins and the resulting chemistry of the olefin bond. Using a combination of synthesis and kinetic studies, we are establishing the link between asymmetry in the metal olefin bond and the relative reactivity of the olefin with nucleophiles. Projects include air-sensitive synthetic studies as well as kinetics and mechanistic work.

 

ORGANIC CHEMISTRY

Dalila Kovacs: Research in our lab is directly related to the recent interested in cost-effective replacement of petroleum, the main resources for the chemical industry, with biomass-derived raw materials. Heterogeneous hydrogenolysis is one way to produce chemicals from biomass-derived feedstock. Despite the well-known chemistry of sugars in biological or homogeneous systems, little is know about the heterogeneous catalysis reaction of sugars with hydrogen on metal surfaces. To accurately predict the nature of the products of these reactions is difficult due to the complexity of the hydrogenolysis as a bond cleavage process coupled with the use of heterogeneous systems under high hydrogen pressure. Therefore, the focus of on-going research in our lab is two fold: (1) the mechanistic investigation of heterogeneous catalytic processes as alternatives for green pathways from biomass-based resources toward chemical commodities; and (2) the use of sugars as chiral factors in the hydrogen-transfer processes.

Felix Ngassa: My research group is interested in both synthetic organic and computational organic chemistry. In particular, we are interested in new avenues to nucleoside modification by palladium catalysis, synthesis of modified nucleosides via the Sonogashira reaction, synthetic and computational studies on heterogeneous oligomers, synthesis of carcinogen-nucleoside adducts, and modeling the interaction of natural oncogenes with synthetic peptides.

Robert Smart: My research interests involve the synthesis, fabrication, and testing of high performance polyimide and polybenzoxazole foam composites for TPS applications in low orbit satellites and reusable launch vehicles. Current funded projects include: (1) NASA Commercialization of Polyimide Foams (funded by NASA); (2) Innovative Thermal Insulation Technologies and Lightweight Innovative Composite Tank Concepts (funded by Missile Defense Agency/US Air Force Research); and (3) Lightweight Passive Fire Protection System for Composite Structures and High Temperature (600¿F) Pipe and Equipment Insulation (funded by US Navy).

Randy Winchester: I have an interest in asymmetric synthesis; in particular, the discovery of new methods for asymmetric synthesis. Silicon compounds have found a prominent position in organic synthesis because of the broad number of reactions that are possible, but there have been relatively few applications of organosilanes in asymmetric synthesis. My group is working to develop a method for the synthesis of chiral organosilicon compounds. Two important applications for these compounds are: (1) as chiral auxiliaries in organic synthesis and (2) as chiral NMR shift reagents. More specifically we are investigating nucleophilic substitution reactions at silicon in the presence of a chiral amine. People working in my group use a wide range of analytical techniques such NMR, IR, Mass Spectrometry and Chiral-HPLC to characterize the new compounds they have synthesized. In addition, we often consider concepts involving inorganic chemistry and physical chemistry as we discuss the nature of nucleophilic substitution at silicon and how we can model it computationally.

Laurie Witucki: Research in the Witucki Lab involves the study of a class of enzymes called protein tyrosine kinases. Kinases are enzymes that are implicated in cancer since they are regulators of cellular activities such as cell growth, division, and motility. It is when these normal cellular functions go awry in the cell that oncogenesis may occur. One specific area of investigation in the lab is the peptide substrate specificity of tyrosine kinases. These studies are performed by synthesizing substrates via solid phase peptide synthesis (SPPS), either as individual peptides or as combinatorial libraries of peptides, in order to determine their activity as ligands for the enzyme under investigation. The techniques utilized by members of the lab range from organic chemistry (synthesis, structure determination and purification) to biochemical protein chemistry including bioassays, enzyme kinetics, and ELISA assays.

 

PHYSICAL CHEMISTRY

Christopher Lawrence: Project 1: Vibrational spectroscopy can be used to learn about the motion of molecules in time. However, the experiments that are typically required to obtain this information can be very difficult (if not impossible) to interpret without using molecular modeling. We are currently attempting to model one such set of experiments performed on carbonmonoxymyoglobin.

Project 2: It has recently been discovered that there is a substantial amount of organic material in tropospheric aerosols. One would expect that this organic material would influence the rate of water evaporation from and condensation into these aerosols. However, experiments measuring the rate of water evaporation through a monolayer of butanol show no effect. We are working on modeling this system to try and understand the process by which water evaporates through a monolayer and why this null result is observed.

George McBane: Project 1: In an experimental project in collaboration with S. Schaertel, I am developing a high-accuracy, laser-based instrument for the measurement of isotope abundances of carbon and nitrogen in gas samples. The project involves diode laser spectroscopy, sample preparation, signal processing, and vacuum techniques. Our initial target is the determination of the fractional abundance of carbon-13 in medical and environmental gas samples.

Project 2: In theoretical and computational projects, I am studying molecular energy transfer in collisions and the molecular motions during photochemical processes. Most of these projects are carried out in collaboration with scientists (both experimentalists and theoreticians) elsewhere. They use both classical and quantum mechanical descriptions of the atomic motions. Most of them require some computer programming, and in many cases we run calculations on supercomputers. Most projects are aimed at comparison to and understanding of state-of-the-art experimental results. At present we have projects underway on rotational and vibrational energy transfer in He-CO and Ne-Li_2 collisions, on the dynamics of the H + NH reaction, and on photodissociation of Ar-I_2 van der Waals molecules. The selection of projects changes fairly frequently as new experimental results appear.

Stephanie Schaertel: Project 1: The isotope ratio (for example the ratio of 12C to 13C) in a sample can be a sensitive indicator of that sample's environmental history. Currently, environmental chemists use mass spectroscopy to obtain sensitive and precise measures of isotope ratios. The size and cost of sensitive mass spectrometers precludes in-the-field measurements. We are working on constructing an apparatus that is small, rugged and relatively inexpensive for the measurement of isotope ratios in environmental samples. Our method is based on the use of a narrow-band infrared diode laser. Work on this project spans the disciplines of chemistry and physics and would offer the researcher experience in laser operation, optics, spectroscopy, vacuum techniques, use of electronic instrumentation for data collection and instrument control, instrument construction, gas handling techniques, and quantum mechanical understanding of molecular vibrations.

Project 2: Currently Fourier-transform infrared difference spectroscopy (FTIR-DS) is used to probe structural changes in biochemical systems (for example, mutation-induced modulation of hydrogen bonding to P700, the primary electron donor in photosystem I, as described by R. Wang, V. Sivakumar, Y.Li, K. Redding and G. Hastings in Biochemistry 2003, 42, 9889-9897). FTIR-DS is faced with the challenge of resolving very small differences in locations of absorption maxima (as small as 0.4 wavenumber) in spectra with low signal-to-noise ratios. Our goal is to explore the feasibility of replacing FTIR-DS with a technique based on intrinsically high-resolution diode-laser-based spectroscopy. We plan to apply wavelength modulation spectroscopy (WMS), a technique with which we have previous experience in gas phase samples, to this problem. This project offers the researcher experience in laser operation, FTIR and laser spectroscopy, biochemical methods, and the theory of infrared spectroscopy.

Project 3: Carboxylic acid dimers have been much studied because they are models for hydrogen-bonded systems like DNA base pairs. A recently published paper (J.W. Keller, J. Phys. Chem. A 2004, 108, 4610-4618) presents an infrared and computational study of formic acid hydrogen bonded to trifluoroacetic acid in the gas phase. Dimers containing two different molecules (called bimolecules), such as the formic acid-trifluoroacetic acid one, are especially interesting because they are asymmetrical, like DNA base pairs. The infrared/computational study helps explain why these asymmetrical complexes are often more stable than symmetrical ones. We would like to develop both the experimental and computational parts of this work into a physical chemistry laboratory exercise. This project offers the researcher experience in Fourier Transform Infrared (FTIR) spectroscopy, thermodynamics, gas sample preparation, and computational chemistry.

Project 4: We have recently constructed a low cost (under $5000) Raman spectrometer (B.A. DeGraff, M. Hennip, J. M. Jones, C. Salter, and S. A. Schaertel, Chem. Educator 2002, 7, 15-18). We are interested in modifying this spectrometer to be able to monitor chemical reactions in real time (timescales could not be shorter than seconds). We are also open to working with anyone who would like to develop undergraduate or high school labs using this spectrometer. This project would offer the researcher experience in instrument construction, experimental design, optics, vibrational spectroscopy, and electronic data collection.

Page last modified March 13, 2014