Glycogen catabolism enzymes and protein fractions in the third and fourth larval stages ofAnisakis simplex

Abstract

AbstractExtracts ofAnisakis simplexthird (L3) and fourth (L4) larval stages were assayed for protein content and activity and properties of α-amylase, glucoamylase and glycogen phosphorylase. Protein content in L4 was twice that in L3. SDS–PAGE applied to both larval stages revealed 22 protein fractions in each, including five stage-specific fractions in each larval stage. The L3 extracts contained three amylase isoenzymes: α1, α2 and α3; their molecular weights were 64, 29 and 21 kDa, respectively. Only one amylase isoenzyme (64 kDa) was found in the L4 extracts. Glycogen in L3 was found to be broken down mostly by hydrolysis because of low glycogen phosphorylase activity. The α-amylase activity in L4 was higher than that in L3 by half and the glycogen phosphorylase activity was ten times higher. In addition, the same enzymes isolated from L3 and L4 were found to differ in their properties. These differences could be manifestations of metabolic adaptations ofA. simplexlarvae to host switch from fish (L3) to mammals (L4), i.e. adaptations to a new habitat.