N-METHYL-N-(5-CARBOXYPENTYL)-1-DEOXYNOJIRIMYCIN, A NEW AFFINITY LIGAND FOR THE PURIFICATION OF TRIMMING GLUCOSIDASE-I

The paper describes the synthesis of a new type of affinity resin containing N-methyl-N-(5-carboxypentyl)-1-deoxynojirimycin as the ligand attached to AH-Sepharose 4B, which allows the purification of trimming glucosidase I from a detergent extract of pig liver crude microsomes in one step and with high yield. The structure of the affinity ligand was designed on the basis of the observation that N,N-dialkylated derivatives of 1-deoxynojirimycin do strongly inhibit trimming glucosidase I, but not nonspecific aryl-alpha-glucosidases, including glucosidase II. The specific binding of glucosidase I eliminates the need of additional purification steps with their associated losses which were required with the previously synthesized N-5(-carboxypentyl)-AH-Sepharose 4B resin in order to achieve a homogenous enzyme preparation.