Structural enzymology to deduce the mechanism-of-action of drug metabolizing cytochrome P450s

The cytochrome P450 enzymes are found throughout nature where they catalyze a range of different chemical reactions.

They are of high medical importance as they constitute the major drug metabolizing system in the human body and accidental inhibition of these proteins results in a severe risk of toxicity.

Crystal structures of human cytochrome P450s have been known for almost two decades and these enzymes have been studied with virtually all biophysical and biochemical methods available.

Despite this scrutiny, there is very limited understanding of how structural changes within the active site guide the chemical reaction.

The emergence of time-resolved serial crystallography is a very exciting development that makes it possible to track structural changes of proteins at work.

We propose to apply this completely novel approach to create a three dimensional movie that describes the detailed mechanism-of-action of human cytochrome P450s.

To achieve this, we will explore different experimental setups for time-resolved serial crystallography in collaboration with staff at the Swedish synchrotron MAX IV.

Moreover, we will develop general protocols for triggering enzymatic reactions in crystals for proteins that are not naturally activated by light.

Through this project we will transform structural enzymology by making the highly specialized method time-resolved serial crystallography more generally applicable to different enzyme systems and available to novice users.