Hydroxynitrile lyase and Nitrilase (HNL/NIT)

Hydroxynitrile lyases (HNLs) and nitrilases are two distinct classes of enzymes that facilitate the metabolism and transformation of nitrile-containing compounds. Hydroxynitrile lyases, primarily found in plants, catalyze the reversible breakdown of cyanohydrins into hydrogen cyanide and a carbonyl compound, a process known as cyanogenesis that serves as a chemical defense mechanism [1]. Nitrilases are a broader superfamily of hydrolases that convert nitriles directly into carboxylic acids and ammonia, bypassing amide intermediates [2]. While these enzymes are not established therapeutic targets in human medicine, human homologs such as NIT1 and NIT2 have been identified and are implicated in metabolic regulation and tumor suppression pathways [3]. In the biotechnology sector, both enzyme classes are highly valued as biocatalysts for the industrial synthesis of enantiopure pharmaceutical intermediates due to their high stereoselectivity [4]. Because this entry groups two separate enzyme families with different catalytic mechanisms and biological origins, it does not represent a single, unified therapeutic target [5].

Other names

OxynitrilaseCyanohydrin lyaseNitrile aminohydrolaseNIT1NIT2Omega-amidase

Hydroxynitrile lyases catalyze the reversible cleavage of cyanohydrins into hydrogen cyanide and a carbonyl compound, whereas nitrilases catalyze the direct hydrolysis of nitriles to carboxylic acids and ammonia [1, 2].