title: A "Dock and Lock" Approach to Preparation of Targeted Liposomes.
abstract: We developed a strategy for covalent coupling of targeting proteins to liposomes decorated with a standard adapter protein. This strategy is based on "dock and lock" interactions between two mutated fragments of human RNase I, a 1-15 aa fragment with the R4C amino acid substitution (Cys-tag), and a 21-127-aa fragment with the V118C substitution, (Ad-C). Upon binding to each other, Cys-tag and Ad-C spontaneously form a disulfide bond between the complementary 4C and 118C residues. Therefore, any targeting protein expressed with Cys-tag can be easily coupled to liposomes decorated with Ad-C. Here we describe the preparation of Ad-liposomes followed by coupling them to two Cys-tagged targeted proteins, human vascular endothelial growth factor expressed with N-terminal Cys-tag and a 254-aa long N-terminal fragment of anthrax lethal factor carrying C-terminal Cys-tag. Both proteins retain functional activity after coupling to Ad-C-decorated drug-loaded liposomes. We expect that our "dock and lock" strategy will open new opportunities for development of targeted therapeutic liposomes for research and clinical use.
authors.affiliation: SibTech, Inc., 115A Commerce Drive, Brookfield, CT, 06804, USA. mbacker@sibtech.com.
authors.forename: Marina V
authors.initials: MV
authors.lastname: Backer
authors.affiliation: SibTech, Inc., 115A Commerce Drive, Brookfield, CT, 06804, USA.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Backer
mesh_terms: D019943:Amino Acid Substitution; D001671:Biochemistry / Q000379:methods*; D002846:Chromatography, Affinity; D055767:Immobilized Proteins / Q000737:chemistry; D008055:Lipids / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry; D010455:Peptides / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D012259:Ribonuclease, Pancreatic / Q000378:metabolism
chemical_list: D055767:Immobilized Proteins; D008055:Lipids; D008081:Liposomes; D010455:Peptides; D011092:Polyethylene Glycols; D012259:Ribonuclease, Pancreatic
keywords: Dock and lock; Liposomes; Recombinant targeting proteins; Self-assembled protein complex; Targeted drug delivery