Metabolite Transport in Mitochondria

Localization and kinetics of pyruvate-metabolizing enzymes in relation to aerobic alcoholic fermentation in Saccharomyces cerevisiae CBS 8066 and Candida utilis CBS 621

“…3). The affinity constant for pyruvate was about 0.3 raM, which is near the K m value that has been reported for the pyruvate dehydrogenase complex [14] and the K m value cf pyruvate transport by mitochondria from various sources [18]. These results make clear that, if the in vivo rates of pyruvate or malate oxidation by the two yeasts would be different, this could only result from differences in the intracelhilar concentration of these substrates.…”

The mitochondrial citrate carrier: Metabolic role and regulation of its activity and expression

“…This method, as well as the one used by Kaplan et al (11), after SDS gel electrophoresis of the purified fraction, showed a single polypeptide of an apparent molecular mass of 30-32.6 kDa (10, 11). The properties of the purified carrier, reconstituted into a liposomal system, were similar to those of CiC from intact mitochondria as far as counter anion requirement, substrate specificity, and inhibitor sensitivity are concerned (2,17,18). CiC, reconstituted into liposomes, shows its optimal transport activity using a Triton X-114/phospholipid ratio of 0.8, 6% cardiolipin and when 24 passages through a single Amberlite column were carried out (19).…”

Kinetic limitations in the overall reaction of mitochondrial oxidative phosphorylation accounting for flux‐dependent changes in the apparent ΔGexP/ΔH+ ratio

“…In addition, the lag phase of oligomycin inhibition [14] was neglected. [12] non-competitive KI = 100#M [13] irreversible /max = 7.8 nmol/mg Mitochondria (0.34-0.81 mg mitochondrial protein/ml) were incubated in the presence of an excess of yeast hexokinase (> 3 U/mg protein) and about 5 mM ATP. With the exception of oligomycin, inhibitors were added step by step after stationary rates of respiration had been reached.…”