– Envelope protein which probably plays a role in virus entry into the host cell. Is probably involved in the virus attachment to the host cell surface and associates with the entry/fusion complex (EFC). Needed for fusion and penetration of the virus core into host cell. Vaccinia virus (strain Copenhagen) L1 Protein (E. coli, His & Myc) is expressed in E. coli expression system with N-10xHis and C-Myc tag. The predicted molecular weight is 26.8 kDa and the accession number is P20540.