Light-harvesting complexes of Botryococcus braunii.
Photosynth Res
; 135(1-3): 191-201, 2018 Mar.
Article
de En
| MEDLINE
| ID: mdl-28551868
ABSTRACT
The colonial green alga Botryococcus braunii (BB) is a potential source of biofuel due to its natural high hydrocarbon content. Unfortunately, its slow growth limits its biotechnological potential. Understanding its photosynthetic machinery could help to identify possible growth limitations. Here, we present the first study on BB light-harvesting complexes (LHCs). We purified two LHC fractions containing the complexes in monomeric and trimeric form. Both fractions contained at least two proteins with molecular weight (MW) around 25 kDa. The chlorophyll composition is similar to that of the LHCII of plants; in contrast, the main xanthophyll is loroxanthin, which substitutes lutein in most binding sites. Circular dichroism and 77 K absorption spectra lack typical differences between monomeric and trimeric complexes, suggesting that intermonomer interactions do not play a role in BB LHCs. This is in agreement with the low stability of the BB LHCII trimers as compared to the complexes of plants, which could be related to loroxanthin binding in the central (L1 and L2) binding sites. The properties of BB LHCII are similar to those of plant LHCII, indicating a similar pigment organization. Differences are a higher content of red chlorophyll a, similar to plant Lhcb3. These differences and the different Xan composition had no effect on excitation energy transfer or fluorescence lifetimes, which were similar to plant LHCII.
Mots clés
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Protéines végétales
/
Complexes collecteurs de lumière
/
Chlorophyta
Type d'étude:
Prognostic_studies
Langue:
En
Journal:
Photosynth Res
Sujet du journal:
METABOLISMO
Année:
2018
Type de document:
Article
Pays d'affiliation:
Pays-Bas