Infectious DNA from herpes simplex virus: infectivity of double-stranded and single-stranded molecules.

The infectious units in native and alkalidenatured preparations of DNA of herpes simplex virus were characterized with respect to their sensitivity to Neurospora crassa endonuclease, their sedimentation properties in high-salt, neutral sucrose gradients, and their sensitivity to hydrodynamic shearing forces. Infectious molecules in native preparations were resistant to N. crassa endonuclease, sedimented at 56 S, and were highly sensitive to shearing forces. After alkaline denaturation, infectious molecules became sensitive to the N. crassa enzyme, sedimented at 200 S, and were relatively resistant to shear. We conclude that both intact duplex molecules ([unk]100 x 10(6) daltons) and intact single strands ([unk]50 x 10(6) daltons) are capable of initiating productive infection.