Protein dynamical structure by tryptophan phosphorescence and enzymatic activity in reverse micelles: 1. Liver alcohol dehydrogenase

Subtle perturbations in the conformational state of liver alcohol dehydrogenase incorporated in reverse micelles of sodium bis(2-ethylhexyl) sulfosuccinate in isooctane were monitored by the phosphorescence lifetime of Trp-314. The enzyme in the micellar milieu possesses an overall structure not dissimilar to the native state except for a considerably greater flexibility of the coenzyme-binding domain. While this change in dynamical structure of the macromolecule is shown to account entirely for the decrease in turnover rate with the larger micelles, with the smaller ones inhibition of the catalytic function points to an additional probably direct role of micellar water. © 1988 American Chemical Society.