Single-Molecule Spectroscopy on RC-LH1 Complexes of Rhodopseudomonas acidophila Strain 10050

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• 作者：Paul S. B枚hm ; June Southall ; Richard J. Cogdell ; J眉rgen K枚hler
• 刊名：The Journal of Physical Chemistry B
• 出版年：2013
• 出版时间：March 21, 2013
• 年：2013
• 卷：117
• 期：11
• 页码：3120-3126
• 全文大小：347K
• 年卷期：v.117,no.11(March 21, 2013)
• ISSN：1520-5207

文摘

We have revisited the RC-LH1 complex from Rhodopseudomonas (Rps.) acidophila for single-molecule spectroscopy. For the current study the pigment鈥損rotein complexes were stabilized in the detergent buffer solution using a relatively mild detergent (dodecyl-尾-d-maltoside (DDM) instead of lauryldimethylamine N-oxide (LDAO)). This leads to a significant reduction of the fraction of broken/dissociated RC-LH1 complexes with respect to previous studies and has allowed us to investigate a sufficiently large sample of individual RC-LH1 complexes. For most of the complexes the fluorescence鈥揺xcitation spectra exhibit a narrow spectral feature at the red end of the spectrum. Analysis of the statistics of the spectral properties yields a close resemblance with the results obtained on RC-LH1 complexes from Rps. palustris for which a low-resolution X-ray structure is available. Based on this comparison we come to the conclusion that for both species the RC-LH1 complex can be described by the same structural model, that is, an overall elliptical assembly of pigments that features a gap.