Phosphopantothenoylcysteine synthetase (PPCS)

Phosphopantothenoylcysteine synthetase (PPCS) is an essential enzyme in the biosynthesis of coenzyme A (CoA), catalyzing the second step of converting (R)-4'-phosphopantothenate and L-cysteine to phosphopantothenoylcysteine using ATP (or CTP in bacteria) as an energy source[1][2][3]. This ligase is classified as EC 6.3.2.5. PPCS is vital for cellular function; disruption causes severe metabolic disorders including dilated cardiomyopathy and neurodegeneration, reflecting its universal importance in energy and intermediary metabolism[1]. While not a conventional drug target, its pathway is a potential locus for rare disease intervention, particularly in inborn errors of CoA synthesis where substrate replacement (e.g., pantethine) may compensate for enzymatic deficiency[1].

Other names

Phosphopantothenate--cysteine ligasePPC synthetaseCOABCMD2CFLJ11838

Enzyme inhibition (theoretically, targeting PPCS would impair CoA biosynthesis) Pantethine supplementation may bypass the enzymatic step in deficiency states