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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

The role of water and structure on the generation of reactive oxygen species in peptide/hypericin complexes

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Souza, Marcia I. [1] ; Silva, Emerson R. [1] ; Jaques, Ygor M. [1] ; Ferreira, Fabio F. [1] ; Fileti, Eudes E. [2] ; Alves, Wendel A. [1]
Total Authors: 6
[1] Univ Fed ABC, Ctr Ciencias Nat & Humanas, BR-09210170 Santo Andre, SP - Brazil
[2] Univ Fed Sao Paulo, Inst Ciencia & Tecnol, BR-12231280 Sao Jose Dos Campos, SP - Brazil
Total Affiliations: 2
Document type: Journal article
Source: JOURNAL OF PEPTIDE SCIENCE; v. 20, n. 7, SI, p. 554-562, JUL 2014.
Web of Science Citations: 16

Hybrid associates formed between peptide assemblies and fluorophores are attractive mainly because of their unique properties for biomedical applications. Recently, we demonstrated that the production of reactive oxygen species (ROS) by hypericin and their stability in excited states are enhanced upon conjugation with l,l-diphenylalanine microtubes (FF-MNTs). Although the detailed mechanisms responsible for improving the photophysical properties of ROS remain unclear, tentative hypotheses have suggested that the driving force is the growth of overall dipolar moments ascribed either to coupling between aligned H2O dipoles within the ordered structures or to the organization of hypericin molecules on peptide interfaces. To provide new insights on ROS activity in hypericin/FF-MNTs hybrids and further explore the role of water in this respect, we present results obtained from investigations on the behavior of these complexes organized into different crystalline arrangements. Specifically, we monitored and compared the photophysical performance of hypericin bound to FF-MNTs with peptides organized in both hexagonal (water-rich) and orthorhombic (water-free) symmetries. From a theoretical perspective, we present the results of new molecular dynamics simulations that highlight the distinct hypericin/peptide interaction at the interface of FF-MNTs for the different symmetries. As a conclusion, we propose that although water enhances photophysical properties, the organization induced by peptide structures and the availability of a hydrophobic environment surrounding the hypericin/peptide interface are paramount to optimizing ROS generation. The findings presented here provide useful basic research insights for designing peptide/fluorophore complexes with outstanding technological potential. Copyright (c) 2014 European Peptide Society and John Wiley \& Sons, Ltd. (AU)

FAPESP's process: 13/17193-6 - 1st International Conference on Peptide Materials for Biomedicine and Nanotechnology (PepMat 2013)
Grantee:Wendel Andrade Alves
Support type: Research Grants - Meeting - Abroad
FAPESP's process: 13/12674-6 - Structural investigations on model systems based on amphiphilic peptides
Grantee:Emerson Rodrigo da Silva
Support type: Scholarships in Brazil - Post-Doctorate
FAPESP's process: 08/10537-3 - Study of crystalline pharmaceuticals polymorphs by X-ray powder diffraction and the Rietveld method
Grantee:Fabio Furlan Ferreira
Support type: Research Grants - Young Investigators Grants
FAPESP's process: 08/57805-2 - Institute of Bioanalytics
Grantee:Lauro Tatsuo Kubota
Support type: Research Projects - Thematic Grants
FAPESP's process: 13/12997-0 - Hierarchical self-organization of peptide amphiphiles: fundamental mechanisms and potential applications
Grantee:Wendel Andrade Alves
Support type: Regular Research Grants