t-Butanol: nature's gift for protein isolation

Homogenization in 30% t-butanol is a method with potential for wide applica tion in the isolation of proteins from animal, plant or microbial sources. Unusually, for an organic solvent, t-butanol stabilizes protein structure. It also inhibits enzyme activities and protein/protein interactions. By inh ibiting proteolysis and obviating unwanted protein/protein interactions, th e presence of approximately 30% t-butanol in a homogenization buffer genera lly minimizes the formation of artifacts and gives a higher yield. The pres ence of t-butanol in the homogenate leads naturally on to concentration and fractionation of proteins by three-phase partitioning, simply by the addit ion of increments of ammonium sulfate. In turn, fractions from three-phase partitioning have a low salt content and are thus poised for ion-exchange c hromatography.