Characterization of a Membrane Fraction Containing a b-type Cytochrome.
The various components obtained from etiolated corn (Zea mays L.) coleoptiles were fractionated by differential or sucrose gradient centrifugation. The endoplasmic reticulum, proplastids, Golgi, and mitochondria were localized by enzymic or other markers in the various fractions. A fifth fraction was also characterized. It contains glucan synthetase II activity, binding sites for N-naphthylphthalamic acid, NADH dehydrogenase activity which is both antimycin A- and cyanide-insensitive, and a b-type cytochrome. It is possible that this fraction is plasma membrane and that it may contain the blue-ultraviolet photoreceptor for phototropism in corn.
Jesaitis
A J
AJ
Institut für Biologie III, Freiburg i. Br., West Germany.
Heners
P R
PR
Hertel
R
R