Abiotic Photophosphorylation Model Based on Abiogenic Flavin and Pteridine Pigments
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ORIGINAL ARTICLE
Abiotic Photophosphorylation Model Based on Abiogenic Flavin and Pteridine Pigments Taisiya A. Telegina • Michael P. Kolesnikov Yulia L. Vechtomova • Andrey A. Buglak • Mikhail S. Kritsky
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Received: 5 March 2013 / Accepted: 26 April 2013 / Published online: 21 May 2013 Springer Science+Business Media New York 2013
Abstract A model for abiotic photophosphorylation of adenosine diphosphate by orthophosphate with the formation of adenosine triphosphate was studied. The model was based on the photochemical activity of the abiogenic conjugates of pigments with the polymeric material formed after thermolysis of amino acid mixtures. The pigments formed showed different fluorescence parameters depending on the composition of the mixture of amino acid precursors. Thermolysis of the mixture of glutamic acid, glycine, and lysine (8:3:1) resulted in a predominant formation of a pigment fraction which had the fluorescence maximum at 525 nm and the excitation band maxima at 260, 375, and 450 nm and was identified as flavin. When glycine in the initial mixture was replaced with alanine, a product formed whose fluorescence parameters were typical to pteridines (excitation maximum at 350 nm, emission maximum at 440 nm). When irradiated with the quasi-monochromatic light (over the range 325–525 nm), microspheres in which flavin pigments were prevailing showed a maximum photophosphorylating activity at 375 and 450 nm, and pteridine-containing chromoproteinoid microspheres were most active at 350 nm. The positions and the relative height of maxima in the action spectra correlate with those in the excitation spectra of the pigments, which point to the involvement of abiogenic flavins and pteridines in photophosphorylation.
Abbreviations ADP Adenosine diphosphate ATP Adenosine triphosphate Fl Oxidized form of flavin • FlH Free radical reduced flavin 1 Fl and 3Fl Singlet and triplet excited states of flavin FMN Riboflavin-50 -phosphate (flavin mononucleotide) FAD Flavin adenine dinucleotide Pi Inorganic orthophosphate PPi Inorganic pyrophosphate 1 O2 Singlet oxygen
Keywords Abiogenic model ADP ATP Flavin Pteridine Photophosphorylation Thermal proteinoid Microspheres Action spectra
In the contemporary biosphere, the major energy source for ATP synthesis is solar radiation which is utilized by the photosynthesis apparatus. Through photosynthetic phosphorylation, which takes place in the thylakoid membranes of plant chloroplasts and in the chromatophores of photosynthetic bacteria, the photon energy is converted to the chemical energy of ATP. In non-photosynthesizing organisms, the energy source for ATP synthesis is oxidation of organic products formed during photosynthesis.
T. A. Telegina (&) M. P. Kolesnikov Y. L. Vechtomova A. A. Buglak M. S. Kritsky A. N. Bach Institute of Biochemistry, Russian Academy of Sciences, 33-2, Leninsky Prospekt, Moscow 119071, Russia e-mail: [email protected]
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Introduction Adenosine-50 -triphosphate (ATP) is an energy-rich molecule and its main functio
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