MUTUALLY EXCLUSIVE DOMAIN FOLDING MOLECULAR SWITCH AND METHOD OF SYNTHESIS THEREOF

摘要

The invention is a fusion protein, embodying a mutually exclusive folding domain molecular switch, wherein the free energy released by folding of a first domain of the fusion protein drives an unfolding of a second domain of the fusion protein, and vice versa. The fusion protein is engineered so that folding the first domain unfolds the second domain, and vice versa, making the folded and unfolded states of the domains mutually exclusive. This is accomplished by insertion of an insert protein GCN4 into a surface loop of a target, protein barnase, subject to die topological design, criterion that the N—C terminal length of GCN4 be at least two-times greater than the Cα-Cα length of a surface loop of barnase. In the absence of the ligand AP-1, barnase is more stable and is folded and active. The presence of AP-1 induces folding of GCN4, forcibly unfolding and inactivating barnase.