Hemin inhibits virion-associated reverse transcriptase of murine leukemia virus

Abstract The virion-associated reverse transcriptase activity of Rauscher murine leukemia virus was inhibited by freshly prepared hemin at a concentration of 10 −4 M. When the hemin solution was aged at room temperature for 5 days, the concentration of 50% inhibition decreased to as low as 10 −7 M. Removal of O 2 from the solution partially prevented the aging. The hemin inhibition was reversible and appears to be directed against the enzyme rather than the template. Hemin did not inhibit the activity of reverse transcriptase purified from avian myeloblastosis virus.