Anno2009
AutoriBarsanti L, Evangelista V, Passarelli V, Vesentini N, Coltelli P, Frassanito AM, Gualtieri P
AbstractEuglena gracilis possesses a simple but sophisticated light detecting system, consisting of an eyespot formed by carotenoids globules and a photoreceptor. The photoreceptor of Euglena is characterized by optical bistability, with two stable states. In order to provide important and discriminating information on the series of structural changes that Euglena photoreceptive protein(s) undergoes inside the photoreceptor in response to light, we measured the in vivo absorption spectra of the two stable states A and B of photoreceptor photocycle. Data were collected using two different devices, i.e. a microspectrophotometer and a digital microscope. Our results show that the photocycle and the absorption spectra of the photoreceptor possess strong spectroscopic similarities with a rhodopsin-like protein. Moreover, the analysis of the absorption spectra of the two stable states of the photoreceptor and the absorption spectrum of the eyespot suggests an intriguing hypothesis for the orientation of microalgae toward light.
RivistaPhotochemistry And Photobiology
ISSN0031-8655
Impact factor2.253
Volume85
Pagina inizio304
Pagina fine312
Autori IBFValtere EVANGELISTA, Vincenzo PASSARELLI, Laura BARSANTI, Paolo GUALTIERI, Anna Maria FRASSANITO
Linee di Ricerca IBFMD.P01.020.001
Sedi IBFIBF.PI