Improved purification and enzymatic properties of three forms of reverse transcriptase from avian myeloblastosis virus.

The purification procedure for quantitative recovery of the three molecular forms, alpha, alpha beta and beta 2 of avian reverse transcriptase (Ueno, A., Ishihama, A. and Toyoshima, K. (1982) J. Biochem. 91, 311-322) was improved with respect to removal of nucleases. The three enzyme forms were prepared from avian myeloblastosis virus by CsCl centrifugation and poly(G)-agarose column chromatography. The alpha- and alpha beta-forms of the enzyme were further purified to near homogeneity by column chromatography on heparin agarose and DNA cellulose, respectively. The three enzyme forms thus purified were equally active in influenza virus RNA-directed synthesis of single-strand cDNA. By contrast, the alpha-form enzyme was more active in the single-strand cDNA-directed synthesis of double-strand DNA than the other two enzyme forms.