Adenosine monophosphate deaminase 1 (AMPD1)

Adenosine monophosphate deaminase 1 (AMPD1) is a skeletal muscle-enriched enzyme that catalyzes the deamination of adenosine monophosphate (AMP) to inosine monophosphate (IMP), releasing ammonia in the purine nucleotide cycle[1][3][7]. This reaction is essential for maintaining intracellular energy balance during muscle contraction and preventing excess AMP accumulation by promoting ATP regeneration under conditions of high energy demand[1][2][3][6][7]. AMPD1 deficiency is one of the most common causes of exercise-induced and metabolic myopathies, typically resulting in symptoms like muscle pain and fatigue post-exercise[1][2][3][7]. Metformin, a widely used diabetes medication, can directly inhibit this enzyme, revealing its pharmacological relevance[3]. AMPD1's function and expression are predominantly in skeletal muscle, with minor expression in other tissues; its activity is central to the pathophysiology of several metabolic and neuromuscular disorders[1][3][6].

Other names

AMP deaminase 1AMPD1MADMADAAMP deaminase isoform MMyoadenylate deaminaseAMPD isoform Mskeletal muscle AMPDmyoadenylate deaminaseMMDDAMPDadenosine monophosphate deaminase 1 (isoform M)adenosine monophosphate deaminase-1 (muscle)

Enzyme inhibition (by metformin and experimental inhibitors): prevents AMP deamination, influences cellular energy balance and AMPK signaling Targeting AMPD1 leads to increased AMP levels and activation of AMP-activated protein kinase (AMPK) pathway