Several properties of the LM unit extracted with sodium dodecyl sulfate from Rhodopseudomonas sphaeroides purified reaction centers

摘要: Abstract We describe several characteristics of an LM unit extracted from purified wild-type Rhodopseudomonas sphaeroides reaction centers after treatment with SDS and lauryldimethylamine N -oxide. also studied another preparation called RC-SDS in which a similar detergent the H-chain was not separated unit. The spectral properties both preparations were to those intact centers; main differences blue shift P-865 Q y band narrowing bacteriopheophytin x band. Studies absorbance changes steady light or flash illumination showed that depleted primary electron acceptor I transition metal (Mn), but still able react quinones, partial restoration photochemistry. 10 partly present formed very unstable semiquinone anion. In preparations, presence added flash-induced + decayed dark multiexponential kinetics, apparent half-times ranging between 60 ms 100 s. This recovery accelerated either by absence O 2 (in case only) o -phenanthroline, decreased amplitude signal. From these experiments it concluded site binding secondary quinone II damaged absent; altered this considered result denaturing action detergents, rather than H polypeptide.