Abstract— –A method for isolating a structural subunit, B825, from the B875 core light‐harvesting complex (LHC) of Rhodobacter sphaeroides 2.4.1 (wild‐type) and a B800‐B850(‐) mutant, puc705‐BA, is presented. This method, based on one developed to prepare a similar subunit, B820, from the core LHC of Rhodospirillum rubrum [Miller et al., Biochemistry 26, 5055–5062 (1987)], requires the dissociation of treated chromatophores with the detergent, octyl‐glucoside. A subsequent gel nitration step separates B800‐850 (if present), reaction centers, and free bacteriochlorophyll from the subunit complex. B825 was quantitatively reassociated into an 873 nm absorbing form which resembled the in vivo complex as judged by its absorption properties. The polypeptides in B825 and B800‐850 were isolated by HPLC and identified by N‐terminal amino acid sequencing. Two polypeptides, a and p, were found in each complex in a 1: 1 ratio. The spectral and biochemical properties of the subunits isolated from Rhodospirillum rubrum, Rhodobacter sphaeroides, and Rhodobacter capsulatus are compared.
|Original language||English (US)|
|Number of pages||9|
|Journal||Photochemistry and Photobiology|
|State||Published - Oct 1990|
ASJC Scopus subject areas
- Physical and Theoretical Chemistry