Michael K. Chan

Research Description:

THE RESEARCH in my laboratory is directed towards the crystallographic structural analysis of metalloenzymes. The final crystallographic determination of a metalloprotein not only yields a 3-dimensional picture of the protein itself, but also provides important details regarding the ligand environment of the metals doing the actual chemistry. Such information can be invaluable in devising hypotheses on how a biological metal site might function. My group is presently involved in several projects directed towards solving structures of proteins involved in metal regulation, methyl transfer, and protein degradation.

Armed with this structural information, we hope to seek an understanding of hw metalloenzymes catalyze specific reactions of interest. In many cases evolution has led to a biological catalyst significantly more active or specific than the best man-made systems. We are hopeful that the insights gleaned from these studies might e used to develop a new synthetic catalysts.

Biomimetic chemistry is a complementary approach utilized to understand how a bioinorganic system works. This method emphasizes the synthesis and characterization of model complexes which mimic the structural or functional features of a metal center of interest. Such studies can be helpful for probing the critical features of a bioinorganic site by providing a simple system on which to test the importance of various factors on the catalytic activity. This approach is particularly effective when the structural features of the site have been previously determined. Recently, the structures of the MoFe protein of nitrogenase and the tungsten containing aldehyde ferredoxin oxidoreductase protein were elucidated. These have provided critical details regarding the structures and environments of the molybdenum and tungsten cofactors involved in nitrogen fixation and oxygen atom transfer. A second primary goal of my laboratory is to prepare synthetic model compounds for these sites.