Protoporphyrin ix as a possible ancient photosensitizer: Spectral and photochemical studies
- Cite this article as:
- Lozovaya, G.I., Masinovsky, Z. & Sivash, A.A. Origins Life Evol Biosphere (1990) 20: 321. doi:10.1007/BF01808114
Due to the potential special position of protoporphyrin IX in the evolution of photosynthesis, the absorption and fluorescence characteristics of this pigment and its complexes with human serum albumin (HSA) and basic proteinoid have been studied in parallel with their photochemical activity. The most significant change in the absorption spectrum of PP IX was the appearance of a new maximum at 455 (or 461) nm in the presence of HSA or proteinoid respectively. Some changes in the physicochemical properties of PP IX in different microenvironments have been detected by changes in fluorescence emission and excitation spectra (intensity, quantum yields, position of maxima). The increase of fluorescence quantum yield resulting from the formation of PP IX complexes with HSA or proteinoid correlates with the increase of their photochemical activity. Results obtained are discussed from the point of view of the early evolution of the photosynthetic apparatus.