title: Synthesis of a pH-sensitive nitrilotriacetic linker to peptide transduction domains to enable intracellular delivery of histidine imidazole ring-containing macromolecules.
abstract: Intracellular delivery of functional macromolecules using peptide transduction domains (PTDs) is an exciting technology with both experimental and therapeutic applications. Recent data indicate that PTD-mediated transduction occurs via fluid-phase macropinocytosis involving an intracellular pH drop to approximately 5. Nitrilotriacetic acid (NTA)-coordinated metals avidly bind hexahistidine-tagged macromolecules, including peptides and proteins. Histidine's imidazole ring has a pK(a) of 6, making this an attractive target for the biological pH drop of PTD-mediated macropinocytotic delivery. The objective of this study was to develop a pH-sensitive PTD delivery peptide (NTA(3)-PTD). We demonstrate the in vitro function of this novel peptide by delivering fluorescently labeled peptides (1.6 kDa) and functional enzymes, beta-galactosidase (119 kDa) and Cre recombinase (37 kDa). Furthermore, the NTA(3)-PTD peptide was able to deliver functional Cre recombinase in an in vivo mouse model.
authors.affiliation: Howard Hughes Medical Institute and Department of Cellular & Molecular Medicine, University of California San Diego School of Medicine, 9500 Gilman Drive, La Jolla, California 92093-0686, USA.
authors.forename: Ronald K
authors.initials: RK
authors.lastname: June
authors.forename: Khirud
authors.initials: K
authors.lastname: Gogoi
authors.forename: Akiko
authors.initials: A
authors.lastname: Eguchi
authors.forename: Xian-Shu
authors.initials: XS
authors.lastname: Cui
authors.forename: Steven F
authors.initials: SF
authors.lastname: Dowdy
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D004195:Disease Models, Animal; D004337:Drug Carriers / Q000737:chemistry; D016503:Drug Delivery Systems; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006639:Histidine / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007093:Imidazoles / Q000737:chemistry*; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D046911:Macromolecular Substances / Q000737:chemistry; D051379:Mice; D008822:Mice, Transgenic; D009571:Nitrilotriacetic Acid / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D010455:Peptides / Q000737:chemistry*
chemical_list: D004337:Drug Carriers; D007093:Imidazoles; D046911:Macromolecular Substances; D009942:Organometallic Compounds; D010455:Peptides; D006639:Histidine; C029899:imidazole; D008156:Luciferases; D009571:Nitrilotriacetic Acid