title: Melittin as model system for probing interactions between proteins and cyclodextrins.
abstract: Cylcodextrin sugars are cyclic sugars that have a hydrophilic exterior and a hydrophobic center. This enables cyclodextrins to solubilize hydrophobic molecules in aqueous media. Cyclodextrins may inhibit aggregation by intercalating surface aromatic residues and competing with interprotein aromatic clusters (pi-pi interactions). In order to investigate this concept, the interaction of hydroxypropyl-beta-cyclodextrin (HPBCD) with melittin is studied with steady-state and time-resolved fluorescence, fluorescence polarization, circular dichroism, and IR spectroscopy. HPBCD inhibits the aggregation of melittin. This inhibition and the spectroscopic results are consistent with the lone aromatic tryptophan of the peptide being intercalated within HPBCD.
authors.affiliation: Department of Biochemistry and Biophysics, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA. mazdak@mail.med.upenn.edu
authors.forename: Mazdak
authors.initials: M
authors.lastname: Khajehpour
authors.forename: Thomas
authors.initials: T
authors.lastname: Troxler
authors.forename: Vikas
authors.initials: V
authors.lastname: Nanda
authors.forename: Jane M
authors.initials: JM
authors.lastname: Vanderkooi
mesh_terms: D000073738:2-Hydroxypropyl-beta-cyclodextrin; D016880:Anisotropy; D002942:Circular Dichroism; D003080:Cold Temperature; D003505:Cyclodextrins / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D005454:Fluorescence Polarization; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D008555:Melitten / Q000737:chemistry* / Q000378:metabolism*; D008958:Models, Molecular; D011485:Protein Binding / Q000187:drug effects; D012492:Salts / Q000494:pharmacology; D013055:Spectrophotometry, Infrared; D013997:Time Factors; D014364:Tryptophan / Q000737:chemistry / Q000378:metabolism; D047392:beta-Cyclodextrins
chemical_list: D003505:Cyclodextrins; D012492:Salts; D047392:beta-Cyclodextrins; D000073738:2-Hydroxypropyl-beta-cyclodextrin; D008555:Melitten; D014364:Tryptophan