A new non-radiochemical method for determination of 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) lyase is described. Acetyl-CoA, the product of the enzymatic reaction, is separated from the substrate by high-performance liquid chromatography and is quantified. The mean 3-hydroxy-3-methylglutaryl-CoA lyase activity in control fibroblasts was 7.8 ± 2.1 (SD) nmol/min per mg protein, and its apparent Km value was 77.8 ± 14.3 μM (R/S mixture) with a calculated Vmax of 12.4 ± 2.2 nmol/min per mg protein. Using this method, we could easily differentiate a patient with 3-hydroxy-3-methylglutaryl-CoA lyase deficiency from control subjects.
- 3-Hydroxy-3-methylglutaric aciduria
- High-performance liquid chromatography
- Hydroxymethylglutaryl-CoA lyase
ASJC Scopus subject areas
- Clinical Biochemistry
- Biochemistry, medical