[A new mandelonitrile lyase from the cherrylaurel (Prunus laurocerasus) (author's transl)].

Mandelonitrile lyase has been isolated from the seeds of Prunus laurocerasus and characterized. The enzyme is a glycoprotein and contains FAD as prosthetic group. It has an absorption spectrum of the hydrophobic type. The molecular weight is 60000. The new mandelonitrile lyase catalyses both formation and cleavage of D-(+)-benzaldehyde cyanohydrin. Despite the existence of marked morphologic and biochemical differences between P. laurocerasus and P. amygdalus (var. sativa) (sweet almond) the enzymes isolated from the seeds of the two Prunoideae species are closely related, as judged from their immunological properties. However they exhibit specific differences in the isoelectric points and quantitative distribution of the three isoenzymes.