Involved in cyanogenesis, the release of HCN from injured tissues. Catalyzes the stereospecific addition of HCN to a variety of aldehydes in vitro. It is a major seed constituent, and could have the additional role of a storage form for reduced nitrogen (By similarity). (R)-mandelonitrile = benzaldehyde + hydrogen cyanide Monomer. Primarily found within protein bodies of the cotyledonary parenchyma cells, with lesser amounts within the procambium. Belongs to the GMC oxidoreductase family.