Abstract: | Mitochondria from AA-cells are a unique model with separately finctioning 1st and 3rd points of energy coupling and with completely blocked 2nd coupling point. In vivo the terminal segment of the respiratory chain does not operate, cytochromes c and a+a3 remain oxidized, and dominating terminal oxidase appears to be a component inhibiting by salicylhydroxamate and bound with the respiratory chain via cytochromes b or ubiquinone pool. The blocking of the 2nd coupling point is due to firm and, probably, quantitative binding of AA with cytochromes b, especially with b559, and also to a partial denaturation of the complex III. |