Professor Bren's research interests lie in the fields of bioinorganic and biophysical chemistry. The Bren group is investigating structure, folding, dynamics, electronic structure, and function of heme proteins in the cytochrome c family. The heme chromophore serves as a valuable spectroscopic probe used in paramagnetic NMR, EPR, resonance Raman, and fluorescence energy transfer experiments. In addition, the Bren group uses a variety of biochemical techniques including site-directed mutagenesis and protein expression. Students taking part in this research have the opportunity to learn a wide range of approaches to a problem.

One major project involves the study of the molecular and electronic structure of the heme group in cytochrome c proteins. The heme in this protein family displays a wide range of structures (from planar to highly ruffled) and redox potentials (with a range of ~ 1 V). A goal of this project is to learn the relationship between structure and function of the heme and its ligating amino acids. As part of this project, the Bren group is developing new NMR methods for characterizing heme structure. The results obtained in this work will help us gain a more complete understanding of how nature controls electron transfer reactions.

The Bren group uses spectroscopy to investigate cytochrome c folding and dynamics.

In a project being done in collaboration with UR Professor Todd Krauss, the Bren group is employing optical methods to study protein folding using cytochrome c as a model system. A primary focus is to characterize the heterogeneity of protein folding by employing single-molecule spectroscopic methods. In addition, the Bren group is developing the use of zinc porphyrin as a fluorescent probe of folding and dynamics of proteins, including proteins that do not normally bind heme. Zinc porphyrin also is a convenient chromophore to utilize in solar energy conversion. In the group’s newest project, zinc porphyrin peptides are being prepared and tested for this application.