Myrosinase

Myrosinase (or thioglucoside glucohydrolase) a family or group of enzymes involved in plant defense against herbivores. Their structure has been elucidated and is available

Myronsinase Activity
Myrosinase is regarded as a defense-related enzyme and is capable of hydrolyzing glucosinolates into various compounds, some of which are toxic. In the presence of water,it cleaves off the glucose group from a glucosinolate. The remaining molecule then quickly converts to a thiocyanate, an isothiocyanate or a nitrile; these are the active substances that serve as defense for the plant. The glucosinolate-myrosinase defensive system is packaged in the plant in a unique manner. The degradative enzymes, myrosinases, which catalyze the hydrolysis of glucosinolate molecules, are largely stored within myrosin grains in myrosin cells, but have also been reported in protein bodies/vacuoles, and as cytosolic enzymes which tend to bind to membranes (Luthy and Matile 1984). When the mechanism isolating the two compounds breaks down, the myrosinase hydrolization of available glucosinolate substrate occurs.