Hydroxymethylglutaryl-CoA synthase is a key enzyme in the mevalonate metabolic pathway, catalyzing the condensation of acetyl-CoA and acetoacetyl-CoA to form hydroxymethylglutaryl-CoA.
Assay principle: HMGCS catalyzes the reaction of acetyl-CoA and acetoacetyl-CoA to produce hydroxymethylglutaryl-CoA along with CoASH, which converts DTNB into the yellow-colored TNB. The product exhibits a characteristic absorbance at 412 nm.