Ilioaia, CristianKruger, T.P.J. (Tjaart)Ilioaia, OanaRobert, BrunoVan Grondelle, RienkGall, Andrew2018-11-022018-02Ilioaia, C., Kruger, T.P.J., Ilioaia, O. et al. 2018, 'Apoprotein heterogeneity increases spectral disorder and a step-wise modification of the B850 fluorescence peak position', Biochimica et Biophysica Acta (BBA) - Bioenergetics, vol. 1859, no. 2, pp. 137-144.0005-272810.1016/j.bbabio.2017.11.003http://hdl.handle.net/2263/67127It has already been established that the quaternary structure of the main light-harvesting complex (LH2) from the photosynthetic bacterium Rhodopseudomonas palustris is a nonameric ‘ring’ of PucAB heterodimers and under low-light culturing conditions an increased diversity of PucB synthesis occurs. In this work, single molecule fluorescence emission studies show that different classes of LH2 ‘rings’ are present in “low-light” adapted cells and that an unknown chaperon process creates multiple sub-types of ‘rings’ with more conformational sub-states and configurations. This increase in spectral disorder significantly augments the cross-section for photon absorption and subsequent energy flow to the reaction centre trap when photon availability is a limiting factor. This work highlights yet another variant used by phototrophs to gather energy for cellular development.en© 2017 Elsevier B.V. All rights reserved. Notice : this is the author’s version of a work that was accepted for publication in Biochimica et Biophysica Acta - Bioenergetics. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. A definitive version was subsequently published in Biochimica et Biophysica Acta - Bioenergetics, vol. 1859, no. 2, pp. 137-144, 2018. doi : 10.1016/j.bbabio.2017.11.003.Light-harvesting complex (LH2)Purple bacteriaSingle molecule spectroscopyPhotosynthesisLow temperatureBacteriochlorophyll (Bchl)Rhodopseudomonas palustrisRhodobacter sphaeroidesPigment organizationPostprint Article