Carboxymethylenebutenolidase homolog (CMBL)

Carboxymethylenebutenolidase homolog (CMBL) is a human enzyme classified as a cysteine hydrolase in the dienelactone hydrolase family, structurally related to bacterial dienelactone hydrolases but representing its only member in the human genome[1][2][7]. CMBL is highly expressed in the cytosol of the liver, intestine, and (to a lesser extent) other tissues, and specifically hydrolyzes cyclic esters, particularly the medoxomil group in several prodrug pharmaceuticals, including olmesartan medoxomil and certain antibiotics[1][3][7]. Its active site contains a critical cysteine residue, and its principal known physiological function is to catalyze conversion of specific prodrugs into their active forms, impacting drug pharmacokinetics and pharmacodynamics[1][3][7]. While its broader endogenous roles remain poorly defined, it is a key determinant in bioactivation of medoxomil-based therapeutic agents and thus represents an actionable target with pharmacological and clinical significance[1][3][7].

Other names

Carboxymethylenebutenolidase homologCMBLFLJ23617JS-1carboxymethylenebutenolidase homolog (Pseudomonas)carboxymethylenebutenolidase-like (Pseudomonas)

Enzymatic hydrolysis: CMBL converts medoxomil ester prodrugs (e.g., olmesartan medoxomil) into their active pharmaceutical metabolites by cleaving the ester bond[1][3][7].