Deficient lipid-protein interaction in mitochondrial cytochrome oxidase from newborn and old rat brain

In contrast to the mature brain, Arrhenius plots of mitochondrial cytochrome c oxidase from newborn and old rat brain show no breaks (transition temperature); the apparent activation energy of the enzyme, in the physiological range of temperature, is also significantly higher. The results indicate deficient lipid-protein interaction as well as differential fluidity status in the inner mitochondrial membranes of the newborn and aged brain. These changes may contribute to the known deficiency in oxygen consumption of the newborn and old brain.