Routing Nanomolar Protein Cargoes to Lipid Raft‐Mediated/Caveolar Endocytosis through a Ganglioside GM1‐Specific Recognition Tag

摘要

There is a pressing need to develop ways to deliver therapeutic macromolecules to their intracellular targets. Certain viral and bacterial proteins are readily internalized in functional form through lipid raft‐mediated/caveolar endocytosis, but mimicking this process with protein cargoes at therapeutically relevant concentrations is a great challenge. Targeting ganglioside GM1 in the caveolar pits triggers endocytosis. A pentapeptide sequence WYKYW is presented, which specifically captures the glycan moiety of GM1 ( = 24 n ). The WYKYW‐tag facilitates the GM1‐dependent endocytosis of proteins in which the cargo‐loaded caveosomes do not fuse with lysosomes. A structurally intact immunoglobulin G complex (580 kDa) is successfully delivered into live HeLa cells at extracellular concentrations ranging from 20 to 160 n , and escape of the cargo proteins to the cytosol is observed. The short peptidic WYKYW‐tag is an advantageous endocytosis routing sequence for lipid raft‐mediated/caveolar cell delivery of therapeutic macromolecules, especially for cancer cells that overexpress GM1.