Hydroxymandelonitrile lyase

In enzymology, a hydroxymandelonitrile lyase is an enzyme that catalyzes the chemical reaction


 * (S)-4-hydroxymandelonitrile $$\rightleftharpoons$$ cyanide + 4-hydroxybenzaldehyde

Hence, this enzyme has one substrate, (S)-4-hydroxymandelonitrile, and two products, cyanide and 4-hydroxybenzaldehyde.

This enzyme belongs to the family of lyases, specifically the aldehyde-lyases, which cleave carbon-carbon bonds. The systematic name of this enzyme class is (S)-4-hydroxymandelonitrile 4-hydroxybenzaldehyde-lyase (cyanide-forming). Other names in common use include hydroxynitrile lyase, oxynitrilase, Sorghum hydroxynitrile lyase, and (S)-4-hydroxymandelonitrile hydroxybenzaldehyde-lyase. This enzyme participates in cyanoamino acid metabolism.

Structural studies
As of late 2007, only one structure has been solved for this class of enzymes, with the PDB accession code.