– Plays a role in the dissolution of the outermost membrane of extracellular enveloped virions (EEV) to allow virion entry into host cells. Participates also in wrapping intracellular mature virions (IMV) to form intracellular enveloped virions (IEV). Vaccinia virus (strain Copenhagen) OPG190 Protein (His & Myc) is expressed in E. coli expression system with N-10xHis and C-Myc tag. The predicted molecular weight is 36.5 kDa and the accession number is P21115.