Viral proteins and adenosine triphosphate phosphohydrolase activity of fish lymphocystis disease virus

Fish lymphocystis disease virus (FLDV) was isolated from papilloma-like lesions of various flatfish species, flounder, dab, and plaice. FLDV particles purified by density gradient centrifugation were denatured and analyzed by polyacrylamide gel electrophoresis under denaturing conditions. At least 33 FLDV polypeptides ranging in molecular weight from 220 to 14 K were detectable after staining with Coomassie blue. The patterns of structural polypeptides from different fish species were similar although some slight and distinct differences were found. In addition, polypeptide patterns of FLDV-infected flatfish cells were analyzed and compared with those of uninfected fish cells. A drastic change in the pattern of host cell proteins is observed and new, virus-induced proteins are synthesized as a result of an in vivo infection by FLDV. A nucleoside triphosphate phosphohydrolase activity is associated with FLDV. The enzymatic activity hydrolyzes the γ-phosphate residue of ATP and GTP with a high preference for ATP. The requirements for the ATPase activity and the reaction products are described.