Alcohol dehydrogenase 1B (ADH1B)

Alcohol dehydrogenase 1B is an enzyme encoded by the human ADH1B gene located on chromosome 4q22. It belongs to the class I family of alcohol dehydrogenases that catalyze the oxidation of ethanol into acetaldehyde—a key step in human ethanol metabolism—using NAD+ as a cofactor and zinc at its active site for substrate positioning. The protein can form homodimers or heterodimers with related subunits (ADH1A, ADH1C), broadening its substrate specificity beyond ethanol to include retinol and various other aliphatic alcohols and steroids. Genetic polymorphisms within this gene—most notably rs1229984—significantly affect enzymatic activity levels among individuals, influencing susceptibility to alcoholism due to differences in how rapidly toxic acetaldehyde accumulates after drinking. Variants also have population-specific distributions linked with reduced risk for alcoholism. Beyond its role in detoxifying ingested ethanol, altered expression or function has been implicated in diseases such as keratoconus and certain cancers where it may influence cell proliferation pathways[6]. The enzyme’s centrality to both normal physiology (alcohol clearance) and pathology makes it a relevant therapeutic target for substance use disorders as well as a potential biomarker for disease risk stratification[2][3][6].

Other names

ADH1BBeta subunit of class I alcohol dehydrogenaseFormerly known as ADH2

Catalyzes oxidation of primary/secondary alcohols to aldehydes/ketones using NAD+ as a cofactor; mechanism involves zinc coordination at the active site for substrate binding and hydride transfer to NAD+.