Deoxyribonuclease activity found in Epstein--Barr virus producing lymphoblastoid cells.

A deoxyribonuclease activity from Epstein--Barr (EB) virus producer lymphocyte cell lines which is correlated with viral production and which is not present in virus non-producer or negative lymphocyte cell lines has been purified 220-fold with 20% recovery and characterized. This nuclease copurifies through diethylaminoethylcellulose column chromatography with the EB virus induced deoxyribonucleic acid (DNA) polymerase in EB virus producer cells which was recently reported by this laboratory, but elutes as a separate peak of activity upon phosphocellulose chromatography. This nuclease activity has a sedimentation coefficient of 4.0 S, a strong divalent cation requirement, an alkaline pH optimum, and the ability to utilize both native and denatured lymphocyte DNA as substrate, reducing both to monophosphonucleosides.