Tuning antenna function through hydrogen bonds to chlorophyll a

Manuel J. Llansola-Portoles, Fei Li, Pengqi Xu, Simona Streckaite, Cristian Ilioaia, Chunhong Yang, Andrew Gall, Andrew A. Pascal*, Roberta Croce, Bruno Robert

*Corresponding author for this work

Research output: Contribution to JournalArticleAcademicpeer-review

Abstract

We describe a molecular mechanism tuning the functional properties of chlorophyll a (Chl-a) molecules in photosynthetic antenna proteins. Light-harvesting complexes from photosystem II in higher plants – specifically LHCII purified with α- or β-dodecyl-maltoside, along with CP29 – were probed by low-temperature absorption and resonance Raman spectroscopies. We show that hydrogen bonding to the conjugated keto carbonyl group of protein-bound Chl-a tunes the energy of its Soret and Qy absorption transitions, inducing red-shifts that are proportional to the strength of the hydrogen bond involved. Chls-a with non-H-bonded keto C131 groups exhibit the blue-most absorption bands, while both transitions are progressively red-shifted with increasing hydrogen-bonding strength – by up 382 & 605 cm−1 in the Qy and Soret band, respectively. These hydrogen bonds thus tune the site energy of Chl-a in light-harvesting proteins, determining (at least in part) the cascade of energy transfer events in these complexes.

Original languageEnglish
Article number148078
Pages (from-to)1-6
Number of pages6
JournalBiochimica et Biophysica Acta - Bioenergetics
Volume1861
Issue number4
Early online date30 Aug 2019
DOIs
Publication statusPublished - 1 Apr 2020

Funding

This work was supported by the ERC funding agency (PHOTPROT project), the French Infrastructure for Integrated Structural Biology (FRISBI) ANR-10-INBS-05 (France) , the Dutch Organization for scientific research via TOP grant (No 84713002 (Netherlands), ) and the European Union's Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No 675006 (SE2B).

FundersFunder number
Dutch Organization for Scientific Research84713002
European Union's Horizon 2020 research and innovation program
Horizon 2020 Framework Programme
H2020 Marie Skłodowska-Curie Actions675006
European Research Council
French Infrastructure for Integrated Structural BiologyANR-10-INBS-05

    Keywords

    • Chl-a
    • Energy regulation
    • Hydrogen bonds
    • Light-harvesting
    • Oxygenic photosynthesis

    Fingerprint

    Dive into the research topics of 'Tuning antenna function through hydrogen bonds to chlorophyll a'. Together they form a unique fingerprint.

    Cite this