Hannover 2010 – wissenschaftliches Programm
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MO: Fachverband Molekülphysik
MO 26: Poster: Biomolecules
MO 26.1: Poster
Donnerstag, 11. März 2010, 16:00–18:30, Lichthof
Spectroscopic Investigation of Reaction-Center Light-Harvesting 1 Complexes from Rhodopseudomonas acidophila - Influences of the Environment — •Paul Böhm1, Ralf Kunz1, Tobias Pflock1, June Southall2, Richard Cogdell2, and Jürgen Köhler1 — 1Experimental Physics IV and Bayreuth Institute of Macromolecular Research (BIMF), University of Bayreuth — 2Division of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, University of Glasgow
Reaction-center (RC) light-harvesting 1 (LH1) complexes from Rhodopseudomonas (Rps.) acidophila were studied in 3 different environments. At first the applicability of the two types of detergents N,N-Dimethyldodecylamnin-N-oxide (LDAO) and n-Dodecyl β-D-maltoside (DDM) for the stabilization of the RC-LH1 complexes was tested. And finally the complexes were also reconstituted into lipid vesicles.
Comparing room-temperature absorption spectra of LDAO- and DDM-stabilized complexes we discerned a slight redshift of 1 nm for the characteristic B875-band in the DDM environment. This redshift which also occured for the reconstituted sample and a better temporal stability of the RC-LH1 complexes in DDM solution, indicate that this detergent is a good mimicry of the natural environment. Low-temperature (1.4 K) fluorescence-excitation and emission spectra of bulk ensembles both showed distinct redshifts (6.6 nm and 8.4 nm), when comparing the detergent-stabilized and the reconstituted samples, reflecting a great structural flexibility for these complexes.