Inter‐relationships between mitochondrial energy conservation at site I, piericidin a sensitivity, and EPR spectra in torulopsis utilis

Spectroscopic resolution of the “iron‐flavoprotein trough” of the respiratory chain of submitochondrial particles from Torulopsis utilis

“…Thus a dual involvement of non-haem iron protein in the segment of the respiratory chain between NADH2 and the cytochromes was suggested. This conclusion was supported by EPR spectroscopy of phenotypically modified submitochondrial particles from T. utih [2] .…”

“…Those from sulphate limited cells [2] resembled those from iron limited cells. Sulphate [3] and iron [l] recovery led to the reappearance of species lb and 2.…”

“…Continuous culture conditions were as described previously [ 1,2] . Iron limited cells were recovered aerobically with 1 PM iron with or without 100 pg cycloheximide/ml [ 1,4] .…”

“…Conditions were also described for the production of cells possessing site I energy conservation but lacking piericidin A sensitivity [2,4] . Thus a dual involvement of non-haem iron protein in the segment of the respiratory chain between NADH2 and the cytochromes was suggested.…”

Changes of mitochondrial NADH2 oxidation pathways in Torulopsis utilis grown on acetate

“…This by-pass allows intramitochondrial NADH, to be oxidized by the respiratory chain in the presence of rotenone, and it also by-passes the energy conservation process at site 1. Evidence against this pathway operating in the absence of rotenone comes from the observation that the presence of site 1 phosphorylation in isolated mitochondria is correlated with a 25-30% increased growth yield of cells in continuous culture, when compared to that of iron deficient cells that lack site 1 [5] . It seems likely, therefore, that controls normally exist to inhibit the by-pass.…”