Author : Ari Asnani

Summary : A Ca(2+) dependent lectin was isolated from the visceral region of golden snail by protein extraction using TBS, 0-25 percent ammonium sulfate fractionation, and column chromatography using gel filtration on Sephadex G-200 followed by Superose-12. Affinity chromatography with fetuin-agarose column was also employed for single step purification. The lectin was present at a concentration 0.25 mg/ml visceral region. An electrophoretically homogeneous from was obtained from Superose-12 column. The apparent molecular weight of the lectin in its native form was estimated by gel filtration analysis to be &860 kDa. On SDS-gel electrophoresis at pH 8.8, a single band corresponding to a &210 kDa protein was observed. This results suggest the possibility that golden snail lectin consists of four identical subunits. From the sedimentation equilibrium experiment, absorption coefficient of the golden snail revealed to be 0.34 at 280 nm whereas the partial specific volume of golden snail lectin was 0.732 ml/g as calculated from its amino acid composition Binding specificity of golden snail lectin on a fetuin-modified sensor surface indicated a monovalent interaction between the lectin and its carbohydrate specific, fetuin, with the pseudo-first order rate constant (K obs) of 0.058 (s -1).