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Titolo:
Orientation and immersion depth of a helical lipopeptaibol in membranes using TOAC as an ESR probe
Autore:
Monaco, V; Formaggio, F; Crisma, M; Toniolo, C; Hanson, P; Millhauser, GL;
Indirizzi:
Univ Padua, CNR, Dept Organ Chem, Biopolymer Res Ctr, I-35131 Padua, ItalyUniv Padua Padua Italy I-35131 Biopolymer Res Ctr, I-35131 Padua, Italy Univ Calif Santa Cruz, Dept Chem & Biochem, Santa Cruz, CA 95064 USA Univ Calif Santa Cruz Santa Cruz CA USA 95064 m, Santa Cruz, CA 95064 USA
Titolo Testata:
BIOPOLYMERS
fascicolo: 3, volume: 50, anno: 1999,
pagine: 239 - 253
SICI:
0006-3525(199909)50:3<239:OAIDOA>2.0.ZU;2-O
Fonte:
ISI
Lingua:
ENG
Soggetto:
ELECTRON-SPIN-RESONANCE; ALANINE-BASED PEPTIDES; TRICHOGIN GA-IV; AMINO-ACID; CONFORMATIONAL-ANALYSIS; STRUCTURAL ELUCIDATION; PHOSPHOLIPID-VESICLES; TOLYPOCLADIUM GEODES; SYNTHETIC ANALOGS; AQUEOUS-SOLUTION;
Keywords:
electron spin resonance; lipopeptaibol; membrane activity; peptide conformation; peptide synthesis;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
57
Recensione:
Indirizzi per estratti:
Indirizzo: Toniolo, C Univ Padua, CNR, Dept Organ Chem, Biopolymer Res Ctr, I-35131 Padua, Italy Univ Padua Padua Italy I-35131 Res Ctr, I-35131 Padua, Italy
Citazione:
V. Monaco et al., "Orientation and immersion depth of a helical lipopeptaibol in membranes using TOAC as an ESR probe", BIOPOLYMERS, 50(3), 1999, pp. 239-253

Abstract

Trichogin GA IV is a lipopeptaibol antibiotic characterized by the sequence nOct-Aib(1)-Gly-Leu-Aib(4)-Gly-Gly-Leu-Aib(8)-Gly-Ile-Lol (nOct: n-octanoyl; Aib: alpha-aminoisobutyric acid; Lol, leucinol), which exhibits membrane-modifying properties. We synthesized step-by-step by solution methods three trichogin analogues, each with a single Aib --> 2,2,6,6-tetramethylpiperidin-1-oxyl-4-amino-4-carboxylic acid (TOAC) substitution. The similarity in the conformational propensities of the C-alpha-tetrasubstituted alpha-amino acids Aib and TOAC allowed us to exploit these analogues to investigate the orientation and therefore the mechanism of action of trichogin in the membranes by the electron spin resonance (ESR) technique. A conformational analysis by Fourier transform ir absorption and CD in different organic solvents and in a membrane-mimetic environment indicated that the conformation of the natural lipopeptaibol remains almost unchanged in the three analogues. Moreover, for all of the analogues permeability measurements revealed membrane-modifying properties comparable to those of trichogin. Our ESR investigation demonstrated that, in liposomes based on phosphatidylcholine, trichogin lays parallel to the membrane surface with its hydrophobic face oriented toward the membrane interior. These results suggest that trichogin might modify membrane permeability via a carpet-like mechanism, at least in liposomes and in the absence of transmembrane potential. (C) 1999 John Wiley &Sons, Inc.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 27/09/20 alle ore 06:48:45