Macrocycle ring deformation as the secondary design principle for light-harvesting complexes
Research output: Contribution to journal › Article
Natural light-harvesting is performed by pigment–protein complexes, which collect and funnel the solar energy at the start of photosynthesis. The identity and arrangement of pigments largely define the absorption spectrum of the antenna complex, which is further regulated by a palette of structural factors. Small alterations are induced by pigment–protein interactions. In light-harvesting systems 2 and 3 from Rhodoblastus acidophilus, the pigments are arranged identically, yet the former has an absorption peak at 850 nm that is blue-shifted to 820 nm in the latter. While the shift has previously been attributed to the removal of hydrogen bonds, which brings changes in the acetyl moiety of the bacteriochlorophyll, recent work has shown that other mechanisms are also present. Using computational and modeling tools on the corresponding crystal structures, we reach a different conclusion: The most critical factor for the shift is the curvature of the macrocycle ring. The bending of the planar part of the pigment is identified as the second-most important design principle for the function of pigment–protein complexes—a finding that can inspire the design of novel artificial systems.
|Research areas and keywords||
Subject classification (UKÄ) – MANDATORY
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|Publication status||Published - 2018 Sep 25|