Biochemical and Immunological Characterization of the DNA Polymerase and RNase H in Feline Leukemia Virus

고양이 백혈병 바이러스의 DNA Porymerase와 RNase H의 생화학적 및 면역학적 연구

Feline leukemia virus DNA polymerase was purified by ion-exchange and nucleic acid affinity chromatographies. The enzyme consists of a single polypeptide chain of approximately 72, 000 molecular weight as determined by both of a glycerol density gradient centrifugation and SDS-polyacrylamide gel electrophoresis. The preferred divalent cation for DNA synthesis is $Mn^2+$ on a variety of template-primers, and its optimum concentration appears to be significantly lower than reported results of other mammalian type-C viral enzymes. The divalent cation requirement for maximum activity of RNase H is similar to those of DNA polymerase. Both DNA polymerase and RNase H activities appear to reside on the same molecule as demonstrated by the copurification of both activities through various purification steps. An additional RNase H without detectible polymerase activity was generated by a limited chymotrypsin digestion. This RNase H activity was inhibited equally effectively as RNase H in the intact reverse transcriptase by antisera prepared against reverse transcriptase of feline leukemia virus. Neutralization and binding test showed that antibody binding to reverse transcriptase molecule did not completely inhibit the polymerase activity.

고양이 백혈병 바이러스에서 reverse transcriptase를 분리하여 생화학적 및 면역학적 연구를 하였다. 분자량은 72,000이고, DNA polymerase와 RNase H의 활성은 0.05-1 mM $M_n^2+$와 50-80 mM KCl에서 가장 좋았다. DNA polymerase와 RNase H는 같은 단백질 분자에 있으며, chymotrypsin 처리로서 RNase H를 쪼개낼 수 있으며, 이 RNase H도 reverse transcriptase의 항체에 의해서 활성이 거의 억제 된다. Reverse transcriptase의 항체 결합위치와 활성을 내는 위치는 다른 것 같다.