ISOLATION OF FRUCTOSE-1,6-BISPHOSPHATASE FROM THE FOOT MUSCLE OF A SNAIL HELIX ASPERSA MAXIMA

The key enzyme of gluconeogenesis D-fructose-1,6-bisphosphate1- phosphohydrolase (EC 3.1.3.11) was isolated from the foot muscle of Helix aspersa maxima for the first time. The specific activity of the isolated enzyme at 25∞C is 13.84 U/mg, the isolation yield being 16%, the degree of protein purification 3310. Electro- phoresis of the isolated FBPase in SDS/PAGE showed one band of ca. 37500 Da. The value is higher than those obtained for the FBPase isolated from the mantle muscle of Mytilus galloprovincialis (27000 Da), but comparable to the results for muscle FBPases of various vertebrate species. The value of I 0.5 for AMP for the purified foot muscle enzyme is 14.95, and Hill coefficient (n) is 1.51. Contrary to the vertebrate muscle enzyme, the snail muscle FBPase shows a lower affinity to AMP.