Alliinase (EC 4.4.1.4) catalyses the production of allicin (thio-2-propene-1-sulfinic acid S-allyl ester), a biologically active compound which is also responsible for the characteristic smell of garlic. It was demonstrated that alliinase which contains 5.5-6% of neutral sugars, gives clear PAS-staining, binds to Con A and can form a complex with garlic mannose-specific lectin (ASA). Evidence that the formation of such a complex is mediated by the interaction of the carbohydrate of the glycoprotein enzyme with the lectin was obtained from a radioligand assay which demonstrated the binding of alliinase to ASA and competitive inhibition of this binding by methyl alpha-D-mannoside. ASA I was shown as the lectin mainly present in the complex with alliinase. The results of this study also demonstrate that alliinase is glycosylated at Asn146 in the sequence Asn146-Met147-Thr148.