Chemistry Projects

Projects are subject to change without advance notice.

The enzyme lysyl oxidase is a copper – dependent enzyme that plays a key role in many biological processes.  Amongst these are the crosslinking of collagen, the modification of the extracellular matrix, and cancer.  Due to the enzyme’s low solubility, there is very little known about the structure of this enzyme.  Over the past 8 months, our research group has published two papers in peer – reviewed journals that have furthered our understanding of this enzyme.  One paper, published in the Protein Journal, identified the amino acid histidine at position 303 in the enzyme sequence as being the amino acid responsible for ensuring that this enzyme functions correctly.  The other paper, published in Cancer Letters, is a minireview outlining the role of lysyl oxidase in breast cancer.  The research proposed below will be used to obtain preliminary data in an effort to visualize lysyl oxidase inside cells.

The green fluorescent protein overexpression system has been used extensively to visualize proteins inside cells because the resulting protein of interest is tagged with a green fluorescent protein that glows green when excited with light at 480 nm.  This is advantageous because lysyl oxidase is difficult to study in situ.  By having a green – glowing tag attached to the protein REVS – UP students will be able to visually track their protein from cell to purified entity.  Once the enzyme has been purified, it can be assayed for activity, formation of cofactor, copper incorporation, etc.  Mutant forms of the enzyme that carry the green fluorescence protein tag will also be generated.

Title: Synthesis and Characterization of Cobalt Organometallic Complexes and Quinones for Use in Biohybrid Dye Sensitized Solar Cells.

Photosystem I (PSI) is one of the key reaction centers of photosynthesis, a protein-pigment super-complex that converts light energy to chemical potential energy with a quantum efficiency approaching 100%. PSI has demonstrated the ability to serve as the photosensitizer in biohybrid dye sensitized solar cells (DSSCs). DSSCs consist of three major components: a photosensitive dye adsorbed onto a TiO₂ semiconductor, a counter electrode, and a redox mediator. The functionality and efficiency of the cell are dependent on the HOMO/LUMO band-gap of the dye, the conduction band of the semiconductor, and the redox potential of the mediator. The traditional I^-/I₃^- redox couple is corrosive to proteins, has a redox potential similar to that of PSI, and absorbs light in the visible spectrum making it unsuitable for a PSI-based solar cell. Current research has focused on cobalt complexes as a redox mediator in biohybrid solar cells as they are not corrosive and offer more negative redox potentials, resulting in a greater driving force for the rereduction of PSI.

This research project will involve the synthesis and characterization of alkyl substituted benzyliminodiacetic acid organometallic cobalt complexes and 4,7-disubstitutedphenanthroline organometallic cobalt complexes as well as substituted quinone molecules to serve as electron mediators in biohybrid-DSSCs.  A major component of this research will be collecting infrared absorption spectra of these series of molecules. Participants will gain knowledge in organic synthesis, preparing samples and gathering/interpreting infrared absorption spectra, how dye sensitized solar cells function, and the scientific method.