title: Amphiphilic CCK peptides assembled in supramolecular aggregates: structural investigations and in vitro studies.
abstract: Supramolecular aggregates obtained by self-aggregation of five new cationic amphiphilic CCK8 peptides have been obtained in water solution and characterized for: (i) aggregate structure and stability; (ii) CCK8 peptide conformation and bioavailability on the external aggregate surface; and (iii) for their cell binding properties. The cationic amphiphilic CCK8 peptides self-aggregate giving a combination of liposomal and micelle structures, with radii ranging between ~60 nm and ~90 nm, and between ~5 and ~10 nm, respectively. The presence of CCK8 peptide well-exposed on the aggregate surface is demonstrated by fluorescence measurements. Peptide conformation changes in the five supramolecular aggregates: the CCK8 conformational behaviour is probably induced by the presence of three charged lysine residues close to the bioactive peptide sequence. Only aggregates in which the CCK8 peptide presents a structural arrangement similar to that found for the same peptide in DPC micelles give promising binding properties to CCK2-R receptors overexpressed by transfected A431 cells. Chemical modifications on the CCK8 N-terminus seem to play an important role in stabilizing the peptide active conformation, either when the peptide derivative is in monomeric or in aggregate form. For their easy preparation procedures and their binding properties, supramolecular aggregates based on cationic peptide amphiphiles can be considered as promising candidates for target selective drug carriers on cancer cells.
authors.affiliation: Department of Biological Sciences, CIRPeB University of Naples Federico II, & IBB CNR, Via Mezzocannone 16, 80134 Naples, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Accardo
authors.forename: Anna
authors.initials: A
authors.lastname: Morisco
authors.forename: Pasquale
authors.initials: P
authors.lastname: Palladino
authors.forename: Rosanna
authors.initials: R
authors.lastname: Palumbo
authors.forename: Diego
authors.initials: D
authors.lastname: Tesauro
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Morelli
mesh_terms: D000595:Amino Acid Sequence; D002766:Cholecystokinin / Q000737:chemistry*; D002942:Circular Dichroism; D005434:Flow Cytometry; D006801:Humans; D046911:Macromolecular Substances / Q000138:chemical synthesis / Q000737:chemistry / Q000493:pharmacokinetics; D008823:Micelles; D015394:Molecular Structure; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry* / Q000493:pharmacokinetics; D013499:Surface Properties; D014018:Tissue Distribution; D014407:Tumor Cells, Cultured
chemical_list: D046911:Macromolecular Substances; D008823:Micelles; D010446:Peptide Fragments; C410885:cholecystokinin 8; D002766:Cholecystokinin