Fluorescence spectroscopy of small peptides interacting with microheterogeneous micelles.

Many peptides containing tryptophan have therapeutic uses and can be studied by their fluorescent properties. The biological activity of these peptides involves interactions with many cellular components and micelles can function as carriers inside organisms. We report results from the interaction o...

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Detalles Bibliográficos
Autores: Romani, Ana Paula, Marquenzin, Cassia Alessandra, Ito, Amando Siuiti
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2010
País:Brasil
Institución:Universidade Federal de Ouro Preto (UFOP)
Repositorio:Repositório Institucional da UFOP
Idioma:inglés
OAI Identifier:oai:repositorio.ufop.br:123456789/4871
Acceso en línea:http://www.repositorio.ufop.br/handle/123456789/4871
https://doi.org/10.1016/j.ijpharm.2009.09.017
Access Level:acceso abierto
Palabra clave:Colloidal carrier
Polymeric micelle
Polymer-surfactant
Tryptophan peptides
Fluorescence
Descripción
Sumario:Many peptides containing tryptophan have therapeutic uses and can be studied by their fluorescent properties. The biological activity of these peptides involves interactions with many cellular components and micelles can function as carriers inside organisms. We report results from the interaction of small peptides containing tryptophan with several microheterogeneous systems: sodium dodecyl sulphate (SDS) micelles; sodium dodecyl sulphate–poly(ethylene oxide) (SDS–PEO) aggregates; and neutral polymeric micelles. We observed that specific parameters, such as wavelength of maximum emission and fluorescence anisotropy, could be used to ascertain the occurrence of interactions. Affinity constants were determined from changes in the intensity of emission while structural modifications in rotameric conformations were verified from time-resolved measurements. Information about the location and diffusion of peptides in the microheterogeneous systems were obtained from tryptophan emission quenching experiments using N-alkylpyridinium ions. The results show the importance of electrostatic and hydrophobic effects, and of the ionization state of charged residues, in the presence of anionic and amphiphilic SDS in the microheterogeneous systems. Conformational stability of peptides is best preserved in the interaction with the neutral polymeric micelles.