Engineering a disulfide-gated switch in streptavidin enables reversible binding without sacrificing binding affinity.

ABSTRACT: Although high affinity binding between streptavidin and biotin is widely exploited, the accompanying low rate of dissociation prevents its use in many applications where rapid ligand release is also required. To combine extremely tight and reversible binding, we have introduced disulfide bonds into opposite sides of a flexible loop critical for biotin binding, creating streptavidin muteins (M88 and M112) with novel disulfide-switchable binding properties. Crystal structures reveal how each disulfide exerts opposing effects on structure and function. Whereas the disulfide in M112 disrupts the closed conformation to increase k_off, the disulfide in M88 stabilizes the closed conformation, decreasing k_off 260-fold relative to streptavidin. The simple and efficient reductio

SUBMITTER: Marangoni JM 

PROVIDER: S-EPMC7385176 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature