title: Influence of structure on binding of chlorophylls to peptide ligands.
abstract: Four classes of chlorophyll (Chl), a, b, c, and d, are involved in photosynthesis within cyanobacteria, algae, and plants. These classes have different evolutionary origins, chemical properties, and biological functions. Our results demonstrate that peptide-bound ligands provided by the imidazole group of histidine and the charge-compensated glutamate-arginine ion pair readily form coordination bonds with Chls a and d but do not interact significantly with Chls b and c. These ligands are apparently not sufficiently strong Lewis bases to displace strongly coordinated water from Chls b and c. These differences determine specificity of binding of Chls in light-harvesting complexes and play an important role in assembly of stable Chl-protein complexes, which has had a profound impact on the evolution of photosynthetic organisms.
authors.affiliation: School of Biological Sciences, University of Sydney, NSW 2006, Australia.
authors.forename: Min
authors.initials: M
authors.lastname: Chen
authors.forename: Laura L
authors.initials: LL
authors.lastname: Eggink
authors.forename: J Kenneth
authors.initials: JK
authors.lastname: Hoober
authors.forename: Anthony W D
authors.initials: AW
authors.lastname: Larkum
mesh_terms: D000595:Amino Acid Sequence; D002734:Chlorophyll / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D013053:Spectrophotometry; D013329:Structure-Activity Relationship
chemical_list: D009842:Oligopeptides; D002734:Chlorophyll