INVESTIGADORES
DANTOLA Maria Laura
congresos y reuniones científicas
Título:
Photosensitization of Proteins and Peptides by Pterin
Autor/es:
DANTOLA, MARIA LAURA; LORENTE, CAROLINA; OLIVEROS, ESTHER; ZURBANO,BEATRIZ N.; CASTAÑO, CAROLINA; THOMAS, ANDRÉS H.
Lugar:
Córdoba
Reunión:
Congreso; 16th International Congress on Photobiology; 2014
Institución organizadora:
International Union of Photobiology
Resumen:
Solar
radiation induces modifications to different biomolecules and is implicated in
the generation of human skin cancers. In particular, UV-A radiation (320-400
nm) can induce damage to DNA and other macromolecules through photosensitized
reactions. This indirect action may be mediated by endogenous or exogenous
photosensitizers and can take place through different mechanisms.
Oxidized pterins, efficient
photosensitizers under UV-A irradiation [1], accumulate in the skin of patients
suffering from vitiligo, a chronic depigmentation disorder [2]. We have
investigated the ability of pterin (Ptr), the parent compound of oxidized
pterins, to photosensitize the oxidation of several substrates: proteins
(albumin, tyrosinase), the peptide a-melanocyte-stimulating
hormone and free amino acids (tryptophan (Trp), tyrosine (Tyr), etc). The mechanism of the
photosensitized processes is initiated by an electron transfer from the
substrate to the triplet excited stated of Ptr. The photosensitized process
produces chemical changes in, at least, two different amino acid residues: Trp
and Tyr. The present findings are analyzed in the context of the general behavior
of pterins as photosensitizers and the biological implications are discussed.
Acknowledgments The
authors thank the CNRS and CONICET financial support.
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