http://www.cnr.it/ontology/cnr/individuo/prodotto/ID9689

Steady-state and femtosecond photoinduced processes of blepharismins bound to alpha-crystallin (Articolo in rivista)

Type

Label

Steady-state and femtosecond photoinduced processes of blepharismins bound to alpha-crystallin (Articolo in rivista) (literal)

Anno

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#doi

Alternative label

Youssef T. (1), Brazard J. (2), Ley C. (2), Lacombat F. (2), Plaza P.(2), M. Martin M. (2), Sgarbossa A. (3), Checcucci G. (3) and Lenci F. (3) (2008)
Steady-state and femtosecond photoinduced processes of blepharismins bound to alpha-crystallin
in Photochemical & photobiological sciences (Print); Royal Society of Chemistry, Cambridge (Regno Unito)
(literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#autori

Youssef T. (1), Brazard J. (2), Ley C. (2), Lacombat F. (2), Plaza P.(2), M. Martin M. (2), Sgarbossa A. (3), Checcucci G. (3) and Lenci F. (3) (literal)

Pagina inizio

Pagina fine

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#url

http://pubs.rsc.org/en/content/articlepdf/2008/pp/b800848e?page=search (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroVolume

Rivista

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#pagineTotali

Note

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#affiliazioni

(1) Cairo University, National Institute of Laser Enhanced Sciences, Giza (Egypt); (2) Ecole Normale Supériure, Départment de Chimie, Paris (France); (3) CNR-IBF, Pisa (literal)

Titolo

Steady-state and femtosecond photoinduced processes of blepharismins bound to alpha-crystallin (literal)

Abstract

The interaction of blepharismin (BP) and oxyblepharismin (OxyBP) with bovine alpha-crystallin (BAC) has been studied both by steady-state and femtosecond spectroscopy, with the aim of assessing the possible phototoxicity of these compounds toward the eye tissues. We showed that these pigments form with BAC potentially harmful ground-state complexes, the dissociation constants of which have been estimated to be 6 +/- 2 mumol L(-1) for OxyBP and 9 +/- 4 mumol L(-1) for BP. Irradiation with steady-state visible light of solutions of blepharismins in the presence of BAC proved to induce a quenching of both the pigment and the intrinsic protein fluorescences. These effects were tentatively rationalized in terms of structural changes of alpha-crystallin. On the other hand, femtosecond transient absorption spectroscopy was used to check the occurrence of any type I photoactivity of oxyblepharismin bound to alpha-crystallin. The existence of a particular type of fast photoinduced reaction, not observed in former studies with human serum albumin but present in the natural oxyblepharismin-binding protein, could here be evidenced but no specific reaction was observed during the first few nanoseconds after excitation. Partial denaturation of alpha-crystallin was however found to alter the excited-state behaviour of its complex with oxyblepharismin, making it partly resemble that of free oxyblepharismin in solution. (literal)

Editore