End-to-end Distance Distribution in Fluorescent Derivatives of Bradykinin in Interaction with Lipid Vesicles

End-to-end Distance Distribution in Fluorescent Derivatives of Bradykinin in Interaction with Lipid Vesicles

Author Montaldi, L. R. Google Scholar
Berardi, M. Google Scholar
Souza, E. S. Google Scholar
Juliano, L. Autor UNIFESP Google Scholar
Ito, A. S. Google Scholar
Institution Universidade de São Paulo (USP)
Universidade Federal de Goiás (UFG)
Universidade Federal de São Paulo (UNIFESP)
Abstract Cellular membranes have relevant roles in processes related to proteases like human kallikreins and cathepsins. As enzyme and substrate may interact with cell membranes and associated co-factors, it is important to take into account the behavior of peptide substrates in the lipid environment. in this paper we report an study based on energy transfer in two bradykinin derived peptides labeled with the donor-acceptor pair Abz/Eddnp (ortho-aminobenzoic acid/N-[2,4-dinitrophenyl]-ethylenediamine). Time-resolved fluorescence experiments were performed in phosphate buffer and in the presence of large unilamelar vesicles of phospholipids, and of micelles of sodium dodecyl sulphate (SDS). the decay kinetics were analyzed using the program CONTIN to obtain end-to-end distance distribution functions f(r). Despite of the large difference in the number of residues the end-to-end distance of the longer peptide (9 amino acid residues) is only 20 % larger than the values obtained for the shorter peptide (5 amino acid residues). the proline residue, in position 4 of the bradykinin sequence promotes a turn in the longer peptide chain, shortening its end-to-end distance. the surfactant SDS has a strong disorganizing effect, substantially broadening the distance distributions, while temperature increase has mild effects in the flexibility of the chains, causing small increase in the distribution width. the interaction with phospholipid vesicles stabilizes more compact conformations, decreasing end-to-end distances in the peptides. Anisotropy experiments showed that rotational diffusion was not severely affected by the interaction with the vesicles, suggesting a location for the peptides in the surface region of the bilayer, a result consistent with small effect of lipid phase transition on the peptides conformations.
Keywords Bradykinin
Phospholipid vesicles
Forster resonance energy transfer
Distance distribution
Peptide-lipid interaction
Language English
Sponsor Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
INCT-FCx, Brazil,
Date 2012-07-01
Published in Journal of Fluorescence. New York: Springer/plenum Publishers, v. 22, n. 4, p. 1151-1158, 2012.
ISSN 1053-0509 (Sherpa/Romeo, impact factor)
Publisher Springer
Extent 1151-1158
Origin http://dx.doi.org/10.1007/s10895-012-1054-0
Access rights Closed access
Type Article
Web of Science ID WOS:000306548600015
URI http://repositorio.unifesp.br/handle/11600/35046

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