Measuring propionyl-CoA carboxylase activity in phytohemagglutinin stimulated lymphocytes using high performance liquid chromatography.

Propionyl-CoA carboxylase (PCC) is a mitochondrial enzyme involved in the catabolism of several essential amino acids and odd chain fatty acids. Previous PCC assays have involved either a radiometric assay or have required mitochondria isolation and/or enzyme purification. We developed an enzymatic method to analyze PCC activity in phytohemagglutinin (PHA) stimulated lymphocytes that involves high performance liquid chromatography. The method shows good linearity and sensitivity. PCC activity was unaffected even when lymphocytes were isolated and PHA stimulated after a whole blood sample had been stored at 4°C for 5days. This indicates that this method is suitable for analyzing samples from distant medical centers. The PCC activity of patients with propionic acidemia was found to be much lower than that of normal individuals and carriers. However, this PCC assay is significantly affected by the red blood cell contamination. In conclusion, this is a reliable method for performing PCC assays and only requires 0.5 to 1.0ml of whole blood from newborns. The PCC assay established in this study is useful for the confirmation of PA in individuals, and prenatal diagnosis and genetic counseling for the affected families.