METABOLIC-FATE OF [H-3] BETA-D-ARABINOFURANOSYL-5-[(E)-2-BROMOVINYL]URACIL IN HERPES-SIMPLEX VIRUS TYPE-1 INFECTED-CELLS

The metabolic fate of 1-beta-D-arabinofuranosyl-5-[(E)-2-bromovinyl (B V-araU) in herpes simplex virus type 1-infected cells was studied usin g tritium-labeled BV-araU, [H-3]BV-araU was selectively taken-up by in fected cells. Approximately 10% of the total uptake of [H-3]BV-araU wa s recovered from the acid-insoluble fraction at any time post-infectio n, Both cellular uptake of [H-3]BV-araU and its incorporation into the acid-insoluble fraction increased with increasing incubation time thr ough 8 hr post-infection, Uptake of [3H]BV-araU and its incorporation into the acid-insoluble fraction also increased proportionally to the duration of exposure to [H-3]BV-araU, An alkaline sucrose gradient sed imentation analysis revealed that the radioactive DNA obtained from ce lls pulse-labeled with [H-3]BV-araU were small DNA fragments which rem ained at the top following a chasing period in isotope-free medium, wh ereas that pulse-labeled with [H-3]thymidine was chased to a fraction of high molecular weight DNA, Nuclease P-1 digestion reduced 99% of th e [H-3]BV-araU-labeled DNA extracted from infected cells to a low mole cular weight, Following digestion of [H-3]BV-araU-labeled DNA with mic rococcal nuclease and spleen exonuclease, all of the radioactivity was recovered as [H-3]BV-araU 3'-monophosphate, Thus, BV-araU strongly in hibits the elongation of viral DNA strands as demonstrated by the alka line sucrose gradient sedimentation analysis, whereas at least a porti on of the [H-3]BV-araU is incorporated inside viral DNA strands in inf ected cells.