The Green Group specializes in the study of inorganic reaction centers.

 

The Green group uses a mixture of theory and experiment to investigate the factors that determine enzymatic reactivity.  We explore the intimate details of protein chemistry with hopes that our insights will be parlayed into advances in medicine and/or improved catalysts for industrial applications.


One area of focus is the role of thiolate ligands in oxidative heme chemistry.  Thiolate-ligated heme proteins play critical roles in a number of important physiological processes (e.g. the metabolism of xenobiotics, neurotransmission, blood pressure control, and immune defense against tumor cells).  Thiolate-ligated heme enzymes are in that they catalyze the insertion of an oxygen atom, derived either from molecular oxygen or peroxide, into a variety of organic substrates, often with high degrees of regio- and stereo-selectivity.  In order to understand these reactions we study many different metalloproteins including P450’s, chloroperoxidase, myoglobin, catalase, among others.  We are trying to understand what factors determine the ability of these enzymes to transfer oxygen.  They hope is that knowledge gained from these investigations can be used to guide protein or catalyst design, so that the synthetic potential of these reactions can be realized in industrial applications.


The Green group also collaborates with the new neighbors on the 3rd floor of the chemistry building (J. Martin Bollinger, Squire Booker, and Carsten Krebs).  One such project is on an extremely interesting metalloprotein from Chlamydia trachomatis.  All organisms have a protein to help create the building blocks of DNA called ribonucleotide reductase (RNR).  In many organisms including humans and E. coli this protein features a di-iron center and an essential tyrosine radical to carry out the needed chemistry.  However, in C. trachomatis the tyrosine radical was missing.  It was discovered by the Bollinger/Krebs group that RNR in C. trachomatis did not need a tyrosine radical because it featured a Mn-Fe hetero-binuclear center.  This was the first of a new class of RNR.  The Green group collaborates with the Bollinger/Krebs lab to help structurally characterized this novel reactive center.  The Green group uses the various spectroscopic and theoretical techniques available to help with this project including, pulsed EPR, XAS, DFT calculations, and Resonance Raman spectroscopy.


The Green group is an extremely exciting place to work and the projects are alway expanding and changing, so check back!