Molecular Factors Controlling Photosynthetic Light Harvesting by Carotenoids

摘要

Carotenoids are naturally occurring pigments that absorbnlight in the spectral region in which the sun irradiatesnmaximally. These molecules transfer this energy to chloro-nphylls, initiating the primary photochemical events of photo-nsynthesis. Carotenoids also regulate the flow of energy withinnthe photosynthetic apparatus and protect it from photoinducedndamage caused by excess light absorption. To carry out thesenfunctions in nature, carotenoids are bound in discretenpigment protein complexes in the proximity of chlorophylls.nA few three-dimensional structures of these carotenoid com-nplexes have been determined by X-ray crystallography. Thus,nthe stage is set for attempting to correlate the structural infor-nmation with the spectroscopic properties of carotenoids tonunderstand the molecular mechanism(s) of their function innphotosynthetic systems.