Synthesis and Incorporation of Photoactive Chlorin-Heme Dimers into Proteins

Synthesis and Incorporation of Photoactive Chlorin-Heme Dimers into Proteins

Inspired by natural photoactive proteins, chlorin-heme dimers were synthesized starting from a new chlorin e6 derivative. The most abundant photoactive proteins are chlorophyll-containing proteins that form bacterial reaction center or photosystem proteins in plants. These proteins are capable of converting the energy of light into an electron flow using their special chlorophyll molecules capable of photo-oxidation. We have used the chlorin pigment in these dimers, which is a stable chlorophyll analogue, to introduce photoactivity into proteins while the heme acts as the electron acceptor/donor. TO better understand the effect of protein environment on the photoactivity, two different systems were constructed: a peptide carrying a chlorin-heme dimer for a totally synthetic system, and myoglobin with its heme replaced with a chlorin-heme dimer as the semi-artificial system. Here we are presenting our data showing that the chlorin pigment can reduce and oxidize the heme by changing its oxidation state.