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. 1976 Dec;73(12):4282–4286. doi: 10.1073/pnas.73.12.4282

Covalently linked chlorophyll a dimer: A biomimetic model of special pair chlorophyll

Michael R Wasielewski 1, Martin H Studier 1, Joseph J Katz 1
PMCID: PMC431433  PMID: 16592367

Abstract

The synthesis of a covalent dimer of chlorophyll a which possesses properties strikingly similar to those exhibited by P700 special pair chlorophyll in vivo is described. The covalent dimer is characterized by several spectroscopic techniques. Hydrogen bonding nucleophiles, such as water, primary alcohols, and primary thiols, are effective in generating a species from solutions of 10 μM covalent dimer in hydrophobic solvents which absorbs light near 700 nm. Formation of this in vitro special pair is a rapid, spontaneous process at room temperature. The range of nucleophiles which promote this process suggests that amino acid residues may function in a similar fashion to form P700 in chlorophyll-protein complexes. The photochemical properties of this in vitro special pair mimic those of in vivo P700 species. The 697 nm absorption of the in vitro special pair undergoes photo-bleaching rapidly in the presence of iodine that results in the production of a cation radical which exhibits an electron spin resonance signal similar to that of oxidized P700 observed in Chlorella vulgaris.

Keywords: photosynthesis, photo-reactive chlorophyll, photo-oxidized chlorophyll, chlorophyll-ligand interactions, chlorophyll-protein interactions

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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