Abstract
We have measured reverse transcriptase enzyme activity per virus particle for samples of avian myeloblastosis virus (BAI strain) and murine leukemia virus (RAUSCHER) USing the synthetic template poly(rC)-oligo(dG). Absolute virus concentrations were determined directly by laser beat frequency spectroscopy. Enzyme activity per virion was determined from the slope of the activity plotted as a function of virus concentration. With this reverse transcriptase assay, the minimum activity (expressed as picomoles of dGTP incorporated/virion per hour) is estimated at (28.1 +/- 4.2) X 10(-7) for avian myeloblastosis virus and (1.1 +/- 0.2) X 10(-7) for murine leukemia virus. The sensitivity of this assay, which is determined by the level of incorporated radioactivity measurable above background, is 2.5 X 10(-4) virions for avian myeloblastosis virus (with dGTP specific activity of 8.9 Ci/mmol) and 88 X 10(-4) virions for murine leukemia virus (with dGTP specific activity of 6.52 CI/mmol). These results show that although reverse transcriptase assays can obviously be used to measure relative virus concentrations of equally purified samples of the same virus, they can be very misleading when used to compare the concentrations of different virus species.
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- Baltimore D. RNA-dependent DNA polymerase in virions of RNA tumour viruses. Nature. 1970 Jun 27;226(5252):1209–1211. doi: 10.1038/2261209a0. [DOI] [PubMed] [Google Scholar]
- Dion A. S., Vaidya A. B., Fout G. S. Cation preferences for poly(rC)-oligo(dG)-directed DNA synthesis by RNA tumor viruses and human milk particulates. Cancer Res. 1974 Dec;34(12):3509–3515. [PubMed] [Google Scholar]
- Filbert J. E., McAllister R. M., Nicolson M. O., Gilden R. V., Lennette E. H. RD-114 virus infectivity assay by measurements of DNA polymerase activity and virus group specific antigen. Proc Soc Exp Biol Med. 1974 Feb;145(2):366–370. doi: 10.3181/00379727-145-37812. [DOI] [PubMed] [Google Scholar]
- Fine D. L., Arthur L. O., PLOWMAN J. K., Hillman E. A., Klein F. In vitro system for production of mouse mammary tumor virus. Appl Microbiol. 1974 Dec;28(6):1040–1046. doi: 10.1128/am.28.6.1040-1046.1974. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McCormick J. J., Larson L. J., Rich M. A. RNase inhibition of reverse transcriptase activity in human milk. Nature. 1974 Oct 25;251(5477):737–740. doi: 10.1038/251737a0. [DOI] [PubMed] [Google Scholar]
- Ringold G., Lasfargues E. Y., Bishop J. M., Varmus H. E. Production of mouse mammary tumor virus by cultured cells in the absence and presence of hormones: assay by molecular hybridization. Virology. 1975 May;65(1):135–147. doi: 10.1016/0042-6822(75)90014-8. [DOI] [PubMed] [Google Scholar]
- Salmeen I., Rimai L., Liebes L., Rich M. A., McCormick J. J. Hydrodynamic diameters of RNA tumor viruses. Studies by laser beat frequency light scattering spectroscopy of avian myeloblastosis and Rauscher murine leukemia viruses. Biochemistry. 1975 Jan 14;14(1):134–141. doi: 10.1021/bi00672a023. [DOI] [PubMed] [Google Scholar]
- Sarngadharan M. G., Sarin P. S., Reitz M. S., Gallo R. C. Reverse transcriptase activity of human acute leukaemic cells: purification of the enzyme, response to AMV 70S RNA, and characterization of the DNA product. Nat New Biol. 1972 Nov 15;240(98):67–72. doi: 10.1038/newbio240067a0. [DOI] [PubMed] [Google Scholar]
- Temin H. M., Mizutani S. RNA-dependent DNA polymerase in virions of Rous sarcoma virus. Nature. 1970 Jun 27;226(5252):1211–1213. doi: 10.1038/2261211a0. [DOI] [PubMed] [Google Scholar]
- Waters L. C., Yang W. K. Comparative biochemical properties of RNA-directed DNA polymerases from Rauscher murine leukemia virus and avian myeloblastosis virus. Cancer Res. 1974 Oct;34(10):2585–2593. [PubMed] [Google Scholar]