First solid-state NMR analysis of uniformly (13)C-enriched major light-harvesting complexes from Chlamydomonas reinhardtti and identification of protein and cofactor spin clusters.

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First solid-state NMR analysis of uniformly (13)C-enriched major light-harvesting complexes from Chlamydomonas reinhardtti and identification of protein and cofactor spin clusters.

First solid-state NMR analysis of uniformly (13)C-enriched major light-harvesting complexes from Chlamydomonas reinhardtti and identification of protein and cofactor spin clusters.

Biochim Biophys Acta. 2011 Jan 25;

Authors: Pandit A, Morosinotto T, Reus M, Holzwarth AR, Bassi R, de Groot HJ

The light-harvesting complex II (LHCII) is the main component of the antenna system of plants and green algae and plays a major role in the capture of sun light for photosynthesis. The LHCII complexes have also been proposed to play a key role in the optimization of photosynthetic efficiency through the process of state 1-state 2 transitions and are involved in down-regulation of photosynthesis under excess light by energy dissipation through non-photochemical quenching (NPQ). We present here the first solid-state magic-angle spinning (MAS) NMR data of the major light-harvesting complex (LHCII) of Chlamydomonas reinhardtii, a eukaryotic green alga. We are able to identify nuclear spin clusters of the protein and of its associated chlorophyll pigments in (13)C-(13)C dipolar homonuclear correlation spectra on a uniformly (13)C-labeled sample. In particular, we were able to resolve several chlorophyll 13(1) carbon resonances that are sensitive to hydrogen bonding to the 13(1)-keto carbonyl group. The data show that (13)C NMR signals of the pigments and protein sites are well resolved, thus paving the way to study possible structural reorganization processes involved in light-harvesting regulation through MAS solid-state NMR.

PMID: 21276419 [PubMed - as supplied by publisher]



Source: PubMed