Soluble and chromatin-bound DNA polymerases in developing soybean

Soluble and chromatin-bound DNA polymerases were isolated and partially purified from germinating embryos and 96-hour, etiolated soybean hypocotyls. The homogenization buffer contained 1.2 M sucrose and 30% glycerol to maximize nuclear integrity. Although the specific activity of the chromatin-bound enzyme increased 6-fold during the first 48 hours of germination, most of the polymerase activity (units/g dry wt.) was in the soluble fraction. Observed developmental changes in the polymerase activities were characterized by changes insensitivity to KC1 and Mg 2+. Specific assay conditions indicated that the soluble and chromatin-bound fractions had similar characteristics to DNA polymerase α and β, respectively.