Figure 5.

Kinetics of the incorporation of radioactively labeled bicarbonate into acid-stable metabolites by mitochondrial extracts in the presence of MC-CoA and cofactors. Time course of the incorporation of radioactivity into acid-stable products (A), MG-CoA (B), HMG-CoA (C), or acetoacetate (D). Incubations were carried out either without or with 10 μg of avidin (to inhibit MCCase activity), which was added 2.5 min after the start of the reaction (arrows). Each time point is an independent sample and represents two replicates. Because of the rapid incorporation of NaH¹⁴CO₃, the background radioactivity was impossible to obtain. Therefore, the 0-min time point was derived from samples incubated for 1 min in the presence of 10 μg of avidin.