Expanding Covalent Attachment Sites of Nonnative Chromophores to Encompass the C‐Terminal Hydrophilic Domain in Biohybrid Light‐Harvesting Architectures. Issue 3 (8th February 2018)

• Record Type: Journal Article
• Authors: Hood, Don; Sahin, Tuba; Parkes‐Loach, Pamela S.; Jiao, Jieying; Harris, Michelle A.; Dilbeck, Preston; Niedzwiedzki, Dariusz M.; Kirmaier, Christine; Loach, Paul A.; Bocian, David F.; Lindsey, Jonathan S.; Holten, Dewey
• Is Part Of: ChemPhotoChem. Volume 2:Issue 3(2018)
• Page Start: 300
• Page End: 313
• Publication Date: 2018-02-08
• Subjects: bacteriochlorin -- bacteriochlorophyll -- energy transfer -- photosynthetic antennae -- self-assembly; Photochemistry -- Periodicals; Periodicals; Electronic journals; 541.35
• DOI: 10.1002/cptc.201700182
• Languages: English
• ISSNs: 2367-0932

Abstract

Abstract: Increasing the solar spectral coverage of native photosynthetic antennas can be achieved using biohybrid light‐harvesting (LH) structures comprised of native‐like bacterial photosynthetic peptides and synthetic bacteriochlorins with strong near‐infrared absorption. Four such biohybrids have been prepared wherein synthetic maleimido‐bearing bacteriochlorinBC1‐mal is covalently attached to a Cys residue substituted at either the +1, +5 or +11 position (relative to His‐0) of the 48‐residue β‐peptide of Rb. sphaeroides LH1. In addition, a β‐peptide with Phe substituted for Tyr at the +4 position along with +1Cys was used to examine possible quenching of the excitedBC1 by the Tyr. The β‐peptide analogs, as well as their peptide‐BC1 conjugates when combined with native α‐peptide, and bacteriochlorophyll a (BChl a ) self‐assemble to form αβ‐dyads and therefrom LH1‐type cyclic (αβ) n oligomers. Static and time‐resolved optical studies show that all of the oligomeric assemblies transfer excitation energy from the appendedBC1 to theBChl a array (B875 ) with an average efficiency of 85 %. Abstract : Complex assembly : Four biohybrid antennas, comprised of native‐like bacterial photosynthetic peptides and a synthetic bacteriochlorin with strong NIR absorption, have been prepared to increase the solar spectral coverage versus that of native photosynthetic antennas. Each oligomeric assembly—formed through a two‐tiered self‐assembly process—funnels energy from the appended bacteriochlorin to the bacteriochlorophyll array with an average efficiency of 85 %.