The Influence of Seasonal Variation on Oxidative Phosphorylation in Sub-mitochondrial Particles Prepared from Jerusalem Artichoke Tubers

Abstract

A method for the preparation of sub-mitochondrial particles from Jerusalem artichoke tubers by sonication is described. The particles carried out a rapid oxidation of NADH, succinate, and ascorbate saturated with N′,N′,N,N-tetramethylphenylenediamine (TMPD). The difference spectrum (dithionite reduced minus oxidized) of sub-mitochondrial particles was similar to that of whole mitochondria. In the autumn phosphorylation accompanied electron transport only when supernatant from the preparation procedure was added to the sub-mitochondrial particles in the presence of magnesium. In the winter and spring there was a decrease in the effect of supernatant on phosphorylation, and the sub-mitochondrial particles alone synthesized ATP during substrate oxidation. It is suggested that the reconstitution of phosphorylation in Jerusalem artichoke sub-mitochondrial particles is essentially similar to that observed in beef heart electron transport particles, but that phosphorylation in the former is subject to seasonal variations.