Before revision: We demonstrate that the oft-reported enhanced diffusion of certain enzymes at substrate concentrations above biological concentrations, meaning above kM(the Michaelis-Menten constant ), can be accounted for by dissociation of these oligomericenzymes into their smaller subunits.
After revision: We demonstrate that the oft-reported enhanced diffusion of certain enzymes at substrate concentrations above biological concentrations, meaning above kM(the Michaelis-Menten constant . Moreover, many of the enzymes studied experimentally to date are oligomeric. Urease, a hexamer of subunits, has been considered to be the gold standard demonstrating enhanced diffusion. Here we show that urease and certain other oligomeric enzymes of high catalytic activity above kM dissociate into their smaller subunits.