The Evolutionary Aspects of Coenzyme Photobiochemistry

Abstract

Photochemical processes driven by solar photons have strongly impacted prebiotic accumulation of organic molecules in outer space and on the Earth, and today photosynthesis is an ultimate source of organic matter for biosphere. Moreover, organisms are capable to perceive photons as informational signals governing their adaptation to the environment. The activity of this photobiological world is founded by photoreceptor molecules converting their excitation energy into the energy of chemical bonds or into an informational signal recognisable by cell metabolism regulators. These photoreceptors strongly vary by the apoprotein structure and by their chromophore molecules, which excitation by light starts the physico-chemical events resulting in manifestation of physiological effect. All the variety of chromophores consists, in fact, of only three chemically distinct groups: tetrapyrrols (porphyrins including chlorophylls and the linear tetrapyrrols such as bilins), isoprenoids (carotenes and retinal), and heterocyclic compounds, the derivatives of isoalloxasine and pteridine. The few exceptions fall into very limited taxonomic niches.