Participating Faculty Members
Updated for 2013
Dr. John Berberian
My research examines the structure in liquids by probing the electrical and mechanical environment in which the molecules of the liquid move. The motions of these molecules, translational and rotational, are determined by viscosity and dielectric (polarization) measurements as a function of time. Simple molecular systems are used for these studies over a wide range of temperatures, from room temperature down to liquid nitrogen temperatures.
Dr. Jose Cerda
A study of the behavior of heme cofactors in benzene by using cyclic voltammetry
In many heme proteins it has been proposed that the peripheral groups on the heme cofactor have significant interactions with the surrounding protein medium. These heme-protein interactions sometimes define the role of heme cofactor. We plan to thermodynamically characterize the effects of hydrogen bonding to the peripheral substituent groups on heme a and heme b. These effects will be evaluated by measuring the reduction potentials of the hemes in benzene, an aprotic solvent. When compared to other media, the effects of heme-ligand interactions are magnified in benzene. Electrochemical studies will be performed on the “free” heme cofactors, and in the presence of an interacting ligand (bound heme), by using cyclic voltammetry.
The pH Dependence of the UV/Vis-Spectroscopic and Electrochemical Properties of Hemeproteins and their Fluoride-Bound Adducts
The oxidized state of many heme proteins have a water molecule coordinated to the heme iron. However, what is the effect on the midpoint potential of these heme proteins if the water-bound molecule is displaced? In this study, we will measure the UV/Vis-spectroelectrochemical properties of the fluoride-bound heme protein and compared it to those without fluoride.
In our previous studies with myoglobin, we found that there is a difference between myoglobin and its fluoride-bound adduct. From pH 4.7 to 9.0, the midpoint potential of myoglobin shows a decrease of about 20 mV. The decrease in the midpoint potential can be attributed to the binding of the hydroxide ion (OH-). However, the midpoint potential of the fluoride-bound myoglobin is maintained at about 0 mV (vs SHE) from pH 6.4 to 9.0. But, at lower pH, the midpoint potential decreases down to -45 mV (vs SHE) at pH 4.7. We theorized that a conformational change caused by the displaced water is responsible for the drop in the midpoint potential at pH lower than 6.0.
Dr. Mark Forman
The Forman Research Group is interested in the synthesis and study of novel, non-natural products of theoretical interest. During the summer of 2011, a primary goal will be the continued investigation of pentacyclo[4.3.0.02,4.03,8.05,7]non-4-ene, a highly pyramidalized alkene. Specifically, we will investigate alternative synthetic routes to this alkene and study its reaction chemistry. Students in the Forman group will be exposed to a variety of modern synthetic organic techniques including microwave assisted organic synthesis; a broad range of spectroscopic methods, including NMR, FTIR, and MS. Some students may also be exposed computational methods including molecular mechanics.
Dr. Peter Graham
In my laboratory we are investigating transition metal complexes which might catalyze the reaction of carbon dioxide with other simple molecules such as ethylene, hydrogen, or methanol. To this end, my students and I are synthesizing a variety of compounds containing the transition metals tungsten and molybdenum that can coordinate carbon dioxide and activate it towards such reactions. Gaining a better understanding of how such metal complexes interact with carbon dioxide is paramount to developing new catalysts for carbon dioxide utilization.
Dr. Usha Rao
My research, which involves a combination of field work and lab chemistry, deals with the presence of environmental pollutants in bodies of water such as rivers and lakes. Recently, my undergraduate research students and I have been studying the presence of metals in the water and sediments of 11 rivers in the Susquehanna-Lackawanna watershed of Pennsylvania, which is a major source of pollutants to the Chesapeake Bay. Another recent area of interest has been evaluating acid-rain induced weathering of limestone headstones at a historical cemetery in the Main Line. A third, long-term project in our lab analyzes the presence of radioiodine in water and sediments from Philadelphia, the Great Lakes, and other locations in Eastern North America.
Dr. Mark Reynolds
Our lab studies two heme proteins, FixL and hSlo. FixL is part of a two component oxygen sensing system in S. meliloti that regulates nitrogen fixation and microaerobic respiration. We are interested in how the heme domain senses oxygen and transmits this signal to it's kinase domain as a model for these heme-based sensor proteins. The hSlo protein is a human potassium channel that we have discovered with our colloborators at Penn to be a novel heme sensing protein. We are currently studying a truncated form of this proteins. Students in my laboratory will learn to do site-directed mutagenesis, protein expression, purification and protein characterization with these two novel heme proteins, FixL and hSlo and specificially designed mutants.
Dr. Jean Smolen
Research conducted in my lab focuses on aquatic chemistry. One project studies the fate of organic pollutants in iron-containing oxides and sediments. The other project evaluates the water quality of local streams in the Philadelphia watershed and compares this to the quality of water on Saint Joseph's University's campus. Students who work in my lab are trained to use many different types of instrumentation and design their own experiments with my guidance. Most students from my group have gone on to pursue advanced degrees in Chemistry and Environmental Science.