Understanding the function, regulation and evolution of enzymes with single molecule experiments
Enzymes, like other (bio)polymers, are intrinsically dynamic molecules which exist in a variety of different conformations. Each of these enzyme conformations might have different catalytic activity. Switching between these conformations results in heterogeneities in the rate for substrate conversion, which can be detected when observing single enzyme molecules. Although these fluctuations in the turnover rate are now well-established their biological relevance is still unknown.
We are using an interdisciplinary approach combining methods for the preparation and directed modification of enzymes with single molecule fluorescence and force spectroscopy for the analysis of enzyme behaviour. This approach allows us to generate enzyme variants with different properties and to determine the consequences of a certain modification on the number of accessible conformations and the corresponding interconversion rates. This will ultimately allow us to establish structure-function-DYNAMICS relationships explaining the relationship between conformational dynamics and catalytic activity.