Respiratory electron transport in plasma and thylakoid membrane preparations from the cyanobacterium Anacystis nidulans

摘要

>Plasma and thylakoid membranes were separated and purified from cell-free extracts of Anacystis nidulans by discontinuous sucrose density gradient centrifugation. Plasma membranes contained less than 0.05% (w/w) chlorophyll per protein. Both plasma and thylakoid membranes oxidized horse heart ferrocytochrome c (10 ± 4 and 3 ± 1 data-equation-construct="true" class="math-equation-construct"> data-equation-image="true" class="math-equation-image"> alt="math formula" src="http://onlinelibrary.wiley.com/store/10.1016/0014-5793(86)80149-1/asset/equation/feb20014579386801491-math-si1.gif?v=1&s=4ad4047edcc4a1a0ee151f217899b455aa36020a" class="inlineGraphic" /> data-equation-mathml="true" class="math-equation-mathml" style="display:none"> per mg protein, respectively), with strong inhibition by low concentrations of cyanide, sulfide, azide, carbon monoxide, and salicyl aldoxime. The activity was stimulated 125% by 3.5% Tween 80 and totally suppressed by 100 mM NaCl. Oxidized cytochrome c was reduced by both types of membranes in the presence of NAD(P)H. The results indicate the occurrence of a respiratory chain including cytochrome-c oxidase in both plasma and thylakoid membranes of A. nidulans.