Chemical Probing to Investigate Human Phase I Metabolism and Microbial Protein
Functions and Regulation
Aaron T. Wright, Senior Scientist
Biological Sciences Division
Pacific Northwest National Laboratory, Richland, WA, 99352, USA
We have a keen interest in using chemical biology to understand protein functions, interactions,
and regulatory processes in living microbial systems and in mammalian metabolism. To
interrogate key questions within these realms we use organic chemistry to synthesize chemical
probes that are then deployed in living systems. Characterization of probe targets is then
performed by proteomics, high-resolution fluorescence microscopy, flow cytometry and other
techniques. A primary focus of ours is on the dynamic reversible reduction and oxidation of
protein cysteine thiols, which we believe to be a particularly important means of regulating protein
function. We have probed the cyanobacterium, Cyanothece sp. 51142, to understand how redox
dynamics influence protein function and concomitant production of hydrogen. A second major
effort is on the identification of transporters and proteins associated with nutrient acquisition and
metabolism in microbes and phototrophic microbial mats. Probes have been used with proteomics
and structured illumination microscopy to characterize spatiotemporal uptake and distribution of
B vitamins in microbial communities. We believe our emerging chemical probe technology
coupled to proteomics and microscopy provides unparalleled ‘views’ into microbes and microbial
communities based upon cellular functions. In addition to our microbial studies we are also
exploring the role metabolic disease plays in altering lung and liver metabolism. Two of the most
important risk factors for human morbidity and mortality are exposure to cigarette smoke and
obesity, both of which are associated with chronic inflammation, oxidative stress, and diseases
such as type 2 diabetes mellitus and cancer. We have used activity-based protein profiling to
evaluate the concomitant effects upon cytochrome P450 enzyme activity of tobacco smoke
exposure and obesity.