Effect of novobiocin on DNA synthesis and structure in human lymphoblastoid cells

Abstract

Summary Novobiocin has an inhibitory effect on DNA synthesis in human lymphoblastoid cells similar to that observed with other mammalian cells. A concentration and time-dependent increase in sedimentation of DNA nucleoids, derived from human lymphoblastoid cells, was observed in the presence of novobiocin. No decrease in the degree of negative supercoiling of DNA, determined by sedimentation on sucrose gradients in the presence of ethidium bromide, was obtained when cells were incubated with novobiocin. The latter findings are contrary to results obtained with other mammalian cells. Alteration in sedimentation rate of nucleoids after novobiocin treatment, at concentrations up to 0.25mg/ml, does not correlate with inhibition of DNA synthesis.