Cytochromes and prenylquinones in preparations of cytoplasmic and thylakoid membranes from the cyanobacterium blue green alga anacystis nidulans
Omata, T.; Murata, N.
Biochimica et Biophysica Acta 766(2): 395-402
The cytochrome and prenylquinone compositions were compared for cytoplasmic membranes and thylakoid membranes from the cyanobacterium (blue-green alga) A. nidulans. Reduced-minus-oxidized difference absorption spectra at -196.degree. C indicated that the thylakoid membranes contained photosynthetic cytochromes such as cytochrome f, cytochrome b-559 and cytochrome b6, while cytochromes c-549 and c-552 were detected spectrophotometrically only after their release by sonic oscillation. The cytoplasmic membrane preparation contained 1 or 2 low-potential cytochrome(s) with .alpha.-band maxima at 553 and 559 mm at -196.degree. C, which differed from the cytochromes in the thylakoid membranes. A cytochrome specific to the cytoplasmic membranes was also found by heme-staining after lithium dodecyl sulfate-polyacrylamide gel electrophoresis. Both types of membranes contained the 3 prenylquinones plastoquinone-9, phylloquinone and 5'-monohydroxyphylloquinone, but in different proportions.