title: Stability of the disulfide bond in an avidin-biotin linked chimeric peptide during in vivo transcytosis through brain endothelial cells.
abstract: Drug delivery of potential neuropharmaceuticals with poor intrinsic permeability through the blood-brain barrier (BBB), such as peptides, is facilitated by coupling to a vector that undergoes receptor-mediated transcytosis through the endothelial cells of brain microvessels. When cleavable disulfide linkers are used in the synthesis of such "chimeric peptides", it is crucial that the S-S-bridge is stable during transcytosis. Cleavage within endothelial cells could result in sequestration of the drug moiety instead of passage through the BBB. In the present study the metabolically stable opioid peptide [3 H]DALDA ([3 H]Tyr-DArg-Phe-Lys-NH2 ) was used as a model drug. It was monobiotinylated with the cleavable biotin reagent sulfosuccinimidyl 2-(biotinamido)ethyl-1,3'-dithiopropionate (NHS-SS-biotin) to obtain bio-[3 H]DALDA. The biotinylated peptide was then bound to a vector for brain delivery after intravenous injection in rats, a covalent conjugate of streptavidin and the transferrin receptor monoclonal antibody, OX26. Compared to peptide without vector, brain uptake of bio-[3 H]DALDA after was increased 18-fold to reach 0.12% of the injected dose per g tissue. Transcranial microdialysis was performed for 60 min after an intravenous bolus of chimeric peptide, followed by reverse phase HPLC of dialysate. Stability of the chimeric peptide during transport through the BBB into brain extracellular fluid was concluded from the absence of a peptide peak generated by disulfide cleavage.
authors.affiliation: College of Pharmacy, Sookmyung Women's University, 53-12, Chungpa-Dong, Yongsan-Gu, Seoul 140-742, Korea.
authors.forename: Y S
authors.initials: YS
authors.lastname: Kang
authors.forename: K
authors.initials: K
authors.lastname: Voigt
authors.forename: U
authors.initials: U
authors.lastname: Bickel
mesh_terms: D000700:Analgesics / Q000737:chemistry / Q000493:pharmacokinetics*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000493:pharmacokinetics*; D001360:Avidin / Q000493:pharmacokinetics; D001710:Biotin / Q000493:pharmacokinetics; D001812:Blood-Brain Barrier / Q000502:physiology; D001921:Brain / Q000098:blood supply / Q000378:metabolism*; D002463:Cell Membrane Permeability; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D007202:Indicators and Reagents / Q000493:pharmacokinetics*; D008297:Male; D009842:Oligopeptides / Q000737:chemistry / Q000493:pharmacokinetics*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011990:Receptors, Transferrin / Q000378:metabolism; D019809:Streptavidin / Q000493:pharmacokinetics
chemical_list: D000700:Analgesics; D000911:Antibodies, Monoclonal; D007202:Indicators and Reagents; D009842:Oligopeptides; D011990:Receptors, Transferrin; C063076:tyrosyl-arginyl-phenylalanyl-lysinamide; D001360:Avidin; D001710:Biotin; D019809:Streptavidin