title: Biodistribution of the cyclotide MCoTI-II, a cyclic disulfide-rich peptide drug scaffold.
abstract: Disulfide-rich macrocyclic peptides are promising templates for drug design because of their unique topology and remarkable stability. However, little is known about their pharmacokinetics. In this study, we characterize the biodistribution in mice of Momordica cochinchinensis trypsin inhibitor-II (MCoTI-II), a cyclic three-disulfide-containing peptide that has been used in a number of studies as a drug scaffold. The distribution of MCoTI-II was compared with that of chlorotoxin, which is a four-disulfide-containing peptide that has been used to develop brain tumor imaging agents; dermorphin, which is a disulfide-less peptide; and bovine serum albumin, a large protein. Both MCoTI-II and chlorotoxin distributed predominantly to the serum and kidneys, confirming that they are stable in serum and suggesting that they are eliminated from the blood through renal clearance. Although cell-penetrating peptides have been reported to be able to transport across the blood-brain barrier, MCoTI-II, which is a cell-penetrating peptide, showed no uptake into the brain. The uptake of chlorotoxin was higher than that of MCoTI-II but lower than that of dermorphin, which is considered to have low uptake into the brain. This study provides insight into the behavior of disulfide-rich peptides in vivo. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, 4072, Australia.
authors.forename: Conan K
authors.initials: CK
authors.lastname: Wang
authors.affiliation: Drug Quality and Registration (DruQuaR) Group, Ottergemsesteenweg 460, 9000, Ghent, Belgium.
authors.forename: Sofie
authors.initials: S
authors.lastname: Stalmans
authors.affiliation: Drug Quality and Registration (DruQuaR) Group, Ottergemsesteenweg 460, 9000, Ghent, Belgium.
authors.forename: Bart
authors.initials: B
authors.lastname: De Spiegeleer
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, 4072, Australia.
authors.forename: David J
authors.initials: DJ
authors.lastname: Craik
mesh_terms: D000818:Animals; D001774:Blood Chemical Analysis; D001812:Blood-Brain Barrier / Q000737:chemistry*; D057846:Cell-Penetrating Peptides; D047169:Cyclotides / Q000493:pharmacokinetics*; D004220:Disulfides / Q000737:chemistry; D007668:Kidney / Q000737:chemistry; D051379:Mice; D012604:Scorpion Venoms / Q000493:pharmacokinetics*; D014018:Tissue Distribution
chemical_list: D057846:Cell-Penetrating Peptides; D047169:Cyclotides; D004220:Disulfides; D012604:Scorpion Venoms; C409923:trypsin inhibitor MCoTI-II; C091539:Chlorotoxin
keywords: bioavailability; blood-brain barrier; cyclic peptide; cyclotide; serum stability; toxin; trypsin inhibitor