title: Epstein-Barr virus induction by a serum factor. Purification of a high molecular weight protein that is responsible for induction.
abstract: Serum contains a factor that induces Epstein-Barr virus antigens in latently infected human lymphoblastoid cell lines and that cooperates with chemical inducers. Here we report the purification of a protein that is responsible for the effect. Using ammonium sulphate precipitation, chromatography on DEAE-agarose and cellulose, molecular sieve chromatography on Bio-Gel A-5, and glycerol gradient centrifugation, the factor was enriched about 300,000-fold compared to calf serum. Under neutral conditions, the protein chromatographed as a high molecular weight protein of about 5.5 X 10(5) both in its active and inactive form. Both forms of the molecule sedimented at about 7 s. The factor is an acidic protein with a pI of 5. It seems to be composed of high molecular and low molecular weight subunits. Nanogram amounts of purified factor are sufficient for measurable inducing effects.
mesh_terms: D000818:Animals; D001798:Blood Proteins / Q000302:isolation & purification* / Q000494:pharmacology; D002051:Burkitt Lymphoma; D002417:Cattle; D002460:Cell Line; D002472:Cell Transformation, Viral / Q000187:drug effects; D003470:Culture Media; D004854:Herpesvirus 4, Human / Q000235:genetics*; D006801:Humans; D007700:Kinetics
chemical_list: D001798:Blood Proteins; D003470:Culture Media