title: Susceptibilities of phospholipid membranes containing cholesterol or ergosterol to gramicidin and its derivative incorporated in lysophospholipid micelles.
abstract: Complex formation of gramicidin (GA) and desformylgramicidin (des-GA) with sterols was investigated by measuring the intrinsic Trp fluorescence. In organic solvents, the Trp fluorescence of momeric GA was quenched upon binding either cholesterol or ergosterol, but that of monomeric des-GA was not quenched by adding cholesterol. Both dimeric GA and des-GA bound highly to ergosterol, but not to cholesterol, determined by quenching of Trp fluorescence. Furthermore, GA- and des-GA-loaded lysophosphatidylcholine micelles were incubated with phosphatidylcholine vesicles containing cholesterol or ergosterol. The results showed that both monomeric and dimeric peptides hardly bound to cholesterol incorporated into phospholipid vesicles, but markedly bound to ergosterol incorporated into the bilayer membranes. Interestingly, des-GA bound more specifically to the two sterols than GA. In addition, fluorescence resonance energy transfer analysis showed that des-GA bound more specifically to the two sterol than GA.
authors.affiliation: Department of Environmental Sciences, Faculty of Science, Osaka Women's University, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Yoshida
authors.forename: Tomoyoshi
authors.initials: T
authors.lastname: Mita
authors.forename: Maki
authors.initials: M
authors.lastname: Onda
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000378:metabolism; D002784:Cholesterol / Q000378:metabolism*; D004875:Ergosterol / Q000378:metabolism*; D031541:Fluorescence Resonance Energy Transfer; D006096:Gramicidin / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000378:metabolism; D008244:Lysophosphatidylcholines / Q000737:chemistry; D008823:Micelles; D010713:Phosphatidylcholines / Q000737:chemistry; D010743:Phospholipids / Q000737:chemistry* / Q000378:metabolism; D012997:Solvents / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D008244:Lysophosphatidylcholines; D008823:Micelles; D010713:Phosphatidylcholines; D010743:Phospholipids; D012997:Solvents; D006096:Gramicidin; C060781:desformylgramicidin; D002784:Cholesterol; D004875:Ergosterol