The effect of altered sterol composition on cytochrome oxidase and S-adenosylmethionine: delta 24 sterol methyltransferase enzymes of yeast mitochondria

Arrhenius kinetics of two mitochondrial enzymes, cytochrome oxidase and S-adenosylmethionine: Δ 24 sterol methyltransferase were analyzed in wild-type and sterol mutant strains of yeast. Temperature effects on the enzymes isolated from the ergosterol producing wild-type and nystatin resistant mutants (major sterol Δ⁸(9), 22 ergostadiene-3-β-ol) were compared. Transition temperatures were lower in both mutant strains compared to wild-type. Lipid analysis shows a relationship between sterol content and the temperature dependent transition phases.