title: Purification of viral proteins from avian sarcoma virus QV2.
abstract: A procedure was established whereby most of the major viral proteins were isolated to apparent homogeneity in biologically and immunologically active forms from a single batch of avian sarcoma virus QV2. For the initial step of purification, gently disrupted virions were fractionated by CsCl centrifugation into envelope proteins, RNA-dependent DNA polymerase, and viral core proteins. Further purification of envelope glycoproteins and DNA polymerase was performed by affinity chromatography on agarose columns cross-linked with plant lectins and poly(C), respectively. On the other hand, core proteins were fractionated by a combination of gel filtration and ion-exchange column chromatography into components p27, p19, and p15. The core protein p15 thus isolated retained proteolytic activity even after storage for 6 months. The present study also demonstrated that QV2 p19 is structurally altered from the corresponding protein of avian myeloblastosis virus (AMV), a reference avian leukosis-sarcoma virus having a well-characterized polypeptide composition.
mesh_terms: D004259:DNA-Directed DNA Polymerase / Q000302:isolation & purification; D005779:Immunodiffusion; D008565:Membrane Proteins / Q000302:isolation & purification; D008970:Molecular Weight; D012190:Retroviridae / Q000032:analysis* / Q000201:enzymology; D014764:Viral Proteins / Q000302:isolation & purification*
chemical_list: D008565:Membrane Proteins; D014764:Viral Proteins; D004259:DNA-Directed DNA Polymerase