Pyruvate dehydrogenase (lipoamide) (PDH E1)

The Pyruvate dehydrogenase (lipoamide) (E1) is the rate-limiting enzyme of the mitochondrial pyruvate dehydrogenase complex (PDC), which catalyzes the irreversible oxidative decarboxylation of pyruvate to acetyl-CoA [1, 2]. This reaction serves as the critical bridge between glycolysis and the tricarboxylic acid (TCA) cycle, thereby playing a central role in aerobic energy metabolism and glucose homeostasis [2, 4]. E1 is a heterotetramer composed of two alpha (PDHA1) and two beta (PDHB) subunits and requires thiamine pyrophosphate (TPP) and magnesium as cofactors [1, 3]. Mutations in the E1 subunits, particularly PDHA1, are the most common cause of pyruvate dehydrogenase complex deficiency (PDCD), leading to congenital lactic acidosis and severe neurological impairment [3, 4]. In cancer, E1 activity is often suppressed (the Warburg effect) to favor glycolysis, making it a target for metabolic reprogramming therapies such as dichloroacetate or CPI-613 [5, 6]. Additionally, E1 is regulated by reversible phosphorylation by pyruvate dehydrogenase kinases (PDKs) and phosphatases (PDPs), which are themselves targets for treating metabolic diseases like diabetes and obesity [2, 5].

Other names

Pyruvate dehydrogenase complex E1Pyruvate dehydrogenase (acetyl-transferring)PDH E1PDHA1PDHBPDHCE1E1 component of the pyruvate dehydrogenase complexPyruvate decarboxylase

1. Inhibition of pyruvate dehydrogenase kinases (PDKs) to maintain E1 in an active, dephosphorylated state (e.g., Dichloroacetate, Phenylbutyrate). 2. Direct or indirect inhibition of E1 activity to disrupt mitochondrial metabolism in cancer cells (e.g., CPI-613, Galloflavin). 3. Cofactor supplementation to optimize residual enzyme function in deficiency states (e.g., Thiamine). 4. Stabilization of mutant E1 subunits to prevent degradation (e.g., Dichloroacetate).