Effects of biotin on pyruvate carboxylase, acetyl-CoA carboxylase, propionyl-CoA carboxylase
, and markers for glucose and lipid homeostasis in type 2 diabetic patients and nondiabetic subjects.
Patients are deficient in propionyl-CoA carboxylase
(PCC), an enzyme that utilizes certain amino acids found in protein.
Since the propionyl-CoA carboxylase
enzyme reaction is reversible, propionyl-CoA accumulates and conjugates to free carnitine to produce propionylcarnitine (Fig.
Samples obtained from the original NBS specimens of confirmed cases with [beta]-cystathionine synthase deficiency (n = 4), propionyl-CoA carboxylase
deficiency (n = 2), methylmalonyl-CoA mutase deficiency (n = 4), Cbl C deficiency (n = 7), various remethylation disorders [methylenetetrahydrofolate reductase (MTHFR), n = 3; Cbl G, n = 3; Cbl D variant 1, n = 1], and maternal vitamin [B.
Normally propionyl-CoA is metabolized to methylmalonyl-CoA by the action of propionyl-CoA carboxylase
(PCC), but if the metabolite is in excess the propionyl species is released from the mitochondrion after conversion by carnitine palmitoyl transferase II to the corresponding acylcarnitine (Fig.
PA results from a deficiency of mitochondrial propionyl-CoA carboxylase
, an enzyme that requires biotin as a cofactor and converts propionyl-CoA to D-methylmalonyl-CoA.
deficiency with overflow of metabolites of isoleucine catabolism at all levels.
PA is caused by deficiency of propionyl-CoA carboxylase
, whereas MMA results from deficiency of either methylmalonyl-CoA mutase or defects in the production of adenosylcobalamin.
Pyroglutamic aciduria in propionyl-CoA carboxylase