LOCATION OF ANTIBODY EPITOPES WITHIN THE MOUSE HEPATITIS-VIRUS NUCLEOCAPSID PROTEIN

Thirteen monoclonal antibodies (Mab) specific for the nucleocapsid (N) protein of mouse hepatitis virus were mapped using a panel of carboxy -terminal N protein truncations expressed by recombinant vaccinia viru ses. All of the Mab recognized both native protein and full-length N p rotein expressed in this vector by both Western blot and enzyme-linked immunoabsorbant assays (ELISA), indicating that they recognized linea r epitopes. The results obtained by both Western blot and ELISA for bi nding to the truncated N proteins coincide for seven of the Mab tested . The linear epitopes recognized localize to four domains dispersed be tween amino acids 171 and 196, 231 and 277, and 374 and 455. The epito pes for six Mab were localized to domains comprising 29 amino acids or less as determined by ELISA. Seven Mab showed different reactivity pa tterns in Western blot versus ELISA, suggesting binding may be influen ced by local conformation. Therefore, the fine specificity of these Ma b could not be determined with certainty. These data represent the fir st determination of antibody binding domains within the mouse hepatiti s virus N protein which forms the viral helical nucleocapsids and appe ars to perform a number of regulatory functions during virus replicati on. (C) 1994 Academic Press, Inc.