Influence of Structure on Binding of Chlorophylls to Peptide Ligands

摘要

Chlorophyll (Ch1) is the essential pigment for oxygenic photosynthesis in cyanobacteria,algae,and plants.Ch1 occurs as four different species among these organisms,and each binds in a highly specific and ordered manner to proteins.Until recently,Ch1 a (see Figure 1 for structures) was thought to be the pigment in reaction centers in all of these organisms.The accessory Chls,Ch1 b and Ch1 c,reside in specific sites in light-harvesting complexes (LHCs),as exemplified by LHCII associated with photosystem II in plants.In 1996,Miyashita et al.discovered a cyanobacterium (Acaryochloris marina) in which over 95% of the Ch1 is Ch1 d.Ch1 d not only is the major light-harvesting pigment in A.marina but also occurs in reaction centers.