Delivery of Superoxide Dismutase Using Cys2-His2 Zinc-Finger Proteins.

Therapeutic proteins have shown great potential in treating life-threatening diseases, but the hydrophilicity and high molecular weight hamper their passing through the cell membrane. Cell-penetrating peptide (CPP)-assisted protein delivery is a simple and efficacious strategy to promote the cellular uptake of therapeutic proteins. We recently demonstrated that the engineered Cys2-His2 zinc-finger domains possess intrinsic cell permeability, which could be leveraged for intracellular protein delivery. Here we applied this method to deliver superoxide dismutase (SOD), a therapeutic protein widely used in preclinical and clinical studies. We present a protocol for the production and delivery of zinc-finger domain-fused SOD. This protocol can be extended for delivering other therapeutic proteins.