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Titolo:
Influence of solvents and leucine configuration at position 5 on tryptophan fluorescence in cyclic enkephalin analogues
Autore:
Malicka, J; Groth, M; Karolczak, J; Czaplewski, C; Liwo, A; Wiczk, W;
Indirizzi:
Univ Gdansk, Fac Chem, PL-80952 Gdansk, Poland Univ Gdansk Gdansk PolandPL-80952 sk, Fac Chem, PL-80952 Gdansk, Poland Adam Mickiewicz Univ, Fac Phys, Quantum Elect Lab, PL-61614 Poznan, PolandAdam Mickiewicz Univ Poznan Poland PL-61614 Lab, PL-61614 Poznan, Poland
Titolo Testata:
BIOPOLYMERS
fascicolo: 4, volume: 58, anno: 2001,
pagine: 447 - 457
SICI:
0006-3525(20010405)58:4<447:IOSALC>2.0.ZU;2-V
Fonte:
ISI
Lingua:
ENG
Soggetto:
DRIVEN MONTE-CARLO; TIME-RESOLVED FLUORESCENCE; MULTIPLE-MINIMA PROBLEM; MEMBRANE-BOUND PORTION; LIFETIME DISTRIBUTIONS; SINGLE-TRYPTOPHAN; CONFORMATIONAL-ANALYSIS; INDOLE FLUORESCENCE; QUENCHING MECHANISM; SECONDARY STRUCTURE;
Keywords:
enkephalin analogues; rime-resolved fluorescence spectroscopy tryptophan fluorescence; rotamers; conformations; theoretical calculations;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
81
Recensione:
Indirizzi per estratti:
Indirizzo: Wiczk, W Univ Gdansk, Fac Chem, Sobieskiego 18, PL-80952 Gdansk, Poland Univ Gdansk Sobieskiego 18 Gdansk Poland PL-80952 Gdansk, Poland
Citazione:
J. Malicka et al., "Influence of solvents and leucine configuration at position 5 on tryptophan fluorescence in cyclic enkephalin analogues", BIOPOLYMERS, 58(4), 2001, pp. 447-457

Abstract

The fluorescence decay of tryptophan is a sensitive indicator of its localenvironment within a peptide or protein. In this study we carried our fluorescence measurements of the tryptophan residue of cyclic enkephalin analogues of a general formula X-c[D-Dab(2)-Gly(3)-Trp(4)-Y-5] where X = Cbz or Hand Y = D- or L-Leu, in four solvents [water, methanol, acetonitrile, and dimethyl sulfoxide (DMSO)]. An analysis of the tryptophan fluorescence decays using a discrete-exponential model indicates that tryptophan fluorescence decay can be described by a double exponential function in all solvents studied. Lifetime distribution analysis yields a bimodal distribution in protic solvents (water and methanol), whereas an asymmetric, unimodal distribution in an aprotic solvent (DMSO) and uni- or bimodal distributions in acetonitrile solution, depending on leucine configuration. The data are interpreted in terms of the rotamer model, in which the modality and the relative proportions of the lifetime components are related to the population distribution of tryptophan chi (1) rotamers about the C-alpha-C-beta bond. The chirality of the Leu(5) residue and solvent properties affect the local environment of the tryptophan residue and therefore influence the distribution of side-chain rotamers. These results are consistent with the results of theoretical conformational calculations. (C) 2001 John Wiley & Sons, Inc. Biopolymers 58: 447-457, 2001.

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Documento generato il 24/09/20 alle ore 05:06:28