Molecular and enzymatic characterization of acid phosphatase from venom of Scleroderma guani

Acid phosphatase (ACPase) is a common component in venom of parasitoids. Although extensive researches regarding this enzyme have been conducted in many other organisms, its characteristics as a venomous enzyme are still sparsely known. In this study, we aimed to reveal the gene expression patterns, and structural and biochemical properties of an ACPase from the venom of Scleroderma guani. The cloned open reading frame of venomous ACPase gene of S. guani was 1218 bp encoding 406 deduced amino acids, shared 40% and 41% identities to ACPases from venoms of Apis mellifera and Pteromalus puparum, respectively. The structural analysis of this ACPase implied common functions and differences to the honeybee venom ACPase. qPCR analysis showed that this gene was abundantly expressed in the venom apparatus, and most highly expressed in the adult stage after one and three days emergence. Activity assay using p-nitrophenyl phosphate as the substrate revealed that the optimal pH and temperature for this venomous enzyme was 4.8 and 45 °C, respectively. NaF is an effective inhibitor for it. The results will enrich our knowledge for the ACPase as toxin, which may contribute to further uncovering its role involved in parasitism.