Activities Comparison,Localization And Molecular Cloning Of Prophenoloxidase In Hameolymph Of Penaeus Chinensis

Biochemical detection demonstrated the presence of phenoloxidase (PO) activity in the hameolymoh of Penaeus chinensis and Penaeus.vannamei. When the hameoly- mph were pretreated with activators such as SDS, trypsin and zymosan, their PO acti- vities increased Significantly,reaching about twice of the untreated.This indicated that the PO activities exist in the hameolymoh of Penaeus chinensis and Penaeus. Vanna- mei as inactive precurseor, prophenoloxidase (proPO). The anticoagulant solution SSS can reduce the PO activities of Penaeus chinensis and Penaeus vannamei. The optim- um temperature for the Penaeus chinensis PO is 50℃,and its optimum PH8.5,he optimum temperature for the Penaeus.vannamei hameolymph PO is 45℃,and its optimum PH7.5. It was show in this thesis that the PO activity existed histochemically in haemo- cyte and its peripheral zone .Most PO were electron-dense and homogenous.Prophenoloxidase is found in both plasma and haemocytes.Propenoloxidase is most abundant in large granule haemocytes,a small abount is present in some small granule haemocytes and hyaline cells,or absent.Two putative copper binding sites are present and they have a highly conserved sequence around these sites.