INVOLVEMENT OF SERINE PROTEINASE IN INFECTIOUS PANCREATIC NECROSIS VIRUS CAPSID PROTEIN MATURATION AND NS PROTEINASE CLEAVAGE IN CHSE-214 CELLS

An investigation of virus-specific protein maturation in infectious pa ncreatic necrosis virus (IPNV) infected Chinook salmon embryo cells (C HSE-214) nas undertaken. The precursor protein (pVP2-1) of the major m ature capsid protein (VP2) was processed sequentially from pVP2-1 to p VP2-2 and VP2. Experiments using serine proteinase inhibitors showed t hat the maturation of the VP2 was blocked in the pVP2-1 post-translati onal cleavage steps.A protinin, a potent proteinase inhibitor, at 800 mu g ml(-1) blocked pVP2-2 to VP2 and the cleavage of VP4 (28 kDa) to VP4-1 (25 kDa). Therefore, our data showed that the maturation of the capsid protein (VP2) and cleavage of VP4 (NS proteinase) can be blocke d by serine proteinase inhibitors.