IndraLab

"We found complex viscosity dependencies and interpreted these in the context of a model in which association and acylation are viscosity-dependent but deacylation is viscosity-independent. (2) The kinetics of inhibition of UCH-L3 by ubiquitin C-terminal aldehyde (Ub-H) were determined and reveal a Ki that is less than 10(-14) M. Several mechanisms are considered to account for the extreme inhibition. (3) The IPaseT-catalyzed hydrolysis of Ub-AMC is modulated by Ub with activation at low [Ub] and inhibition at high [Ub]. (4) Finally, we compare kc/Km values for deubiquitinating enzyme-catalyzed hydrolysis of Ub-AMC and Z-Leu-Arg-Gly-Gly-AMC."