Chemistry Department Seminar: Dr. Steve Presse, Enzymes stepping on landmines

In this two-part talk, I will discuss: 1) how enzymes dissipate catalytic energy and 2) a solution to the 'single molecule counting problem'.
1) Enzymes releasing heat: Enzymes are proteins that are responsible for catalyzing reactions in living systems. Some enzymes perform reactions so exothermic that their own
self-generated heat would be sufficient to unfold over a million small proteins per second. How do enzymes then cope with this heat? Here I will discuss recent work with collaborators where we have shown that enzymes rapidly dissipate heat by accelerating their center of mass.
2) Counting problem: Characterizing protein assemblies — as they occur in their native cellular environment — is a major challenge since these assemblies can involve up to many tens of proteins within approximately a 10nm range. The method I present shows promise in characterizing protein complexes in living cells by using state-of-the-art (superresolution) data already available. That is, I will propose a solution to the counting problem which involves determining how many proteins of type X, say, are in a given complex in living cells. Addressing this problem is a first step in quantitatively characterizing protein-protein interactions which is an essential prerequisite for developing a mechanistic understanding of cell biology and the disease states associated with defective protein complexes.