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. (R)-mandelonitrile = benzaldehyde + hydrogen cyanide Monomer. Primarily found within protein bodies of the cotyledonary parenchyma cells, with lesser amounts within the procambium. Seeds. Localized within cotyledonary parenchyma cells. Absent from maturing black cherry fruits until 6 weeks after flowering. Then, concomitant with cotyledon development, the level of enzyme increases with specificity for embryonal tissues. Glycosylated. Belongs to the GMC oxidoreductase family.