USE OF DODECYL-BETA-D-MALTOSIDE IN THE PURIFICATION AND STABILIZATION OF RNA-POLYMERASE FROM BROME MOSAIC-VIRUS-INFECTED BARLEY

The activity and specificity of RNA-dependent RNA polymerase (replicase) isolated from brome mosaic virus-infected barley was enhanced by extraction with the nonionic detergent dodecyl-.beta.-D-maltoside. The enzyme was stable for at least 8 wk when stored at -70.degree. C. A further 100-fold purification was obtained by centrifugation through sucrose in the presence of detergent. The polymerase activity was associated with the pellet fraction; the template dependence and specificity were similar to those of the enzyme before sucrose purification. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed a 110 kilodalton protein in the purified pellet fraction from infected leaves that was absent from a similar fraction from healthy leaves. The protein had an identical electrophoretic mobility to that of protein 1a, the product of brome mosaic virus RNA 1 translation in vitro, and the profile of its tryptic polypeptides was very similar to that of protein 1a. RNA 1 apparently codes for the viral replicase, or a subunit thereof.