PURIFICATION AND PHYSICOCHEMICAL CHARACTERIZATION OF THE α- GLUCOSIDASE OF THE DIGESTIVE JUICE OF THE SNAIL LIMICOLRIA FLAMMEA (Müller 1774).

In this study we are interested by the α-glucosidase, a protein biocatalyst from the digestive juice of a snail Limicolaria flammea which we purified by the chromatographic methods. Then the physico-chemical characteristics of this enzyme were determined. With a specific activity of the crude extract of 4.31 U/mg, purification have been done on Sephacryl S-200 HR gel then, specific activity has passed to 34.17 U/mg with purification factor of 7,93.With Anx-sepharose 4 fast flow gel, specific activity increased to 92.58U/mg with purification factor of 21.48 and 147 U/mg on phenyl-Sepharose CL 6B with purification factor of 34.11. The apparent molecular weights of the α-glucosidase purified on gel filtration (64,000 Da) and by electrophoresis on polyacrylamide gel (68,200 Da) were nearly identical. With a stability zone of pH between 4 and 7.5, the α- glucosidase had its maximum activity at pH 6.5. Optimum temperature of hydrolysis was obtained at 45°C and was stable at 37 to 40°C. The study of substrate specificity showed that para-nitrophenyl-α-D glucopyranoside and sucrose are hydrolyzed by the enzyme. It was inhibited by Cu2+, Ni2+, Hg2+ and activated by Mn2+. Ideal conditions for activity of this enzyme were known therefore it could be used to achieve synthesis.