Purification of terminal deoxynucleotidyltransferase by oligonucleotide affinity chromatography

Abstract

Terminal deoxynucleotidyltransferase is an enzyme which has been found to be associated with thymus cells, bone marrow cells, as well as leukocytes from patients with acute lymphoblastic leukemia and chronic myelocytic leukemia in blast crisis. We report here the purification of terminal deoxynucleotidyltransferase by an oligonucleotide affinity (oligo(dT)12-18 cellulose) column. By using a 35 to 70% (NH4)2SO4 cut, Sephacryl S200 column and an oligo(dT) cellulose column, terminal deoxynucleotidyltransferase has been purified from calf thymus cells to a specific activity of more than 8,500 units/mg of protein. The terminal deoxynucleotidyltransferase purified by this method contains no detectable DNA-dependent DNA polymerase or endonuclease activities. Furthermore, sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the enzyme appears to be homogeneous, with two polypeptides corresponding to the two subunits alpha (10,000) and beta (23,000) of terminal deoxynucleotidyltransferase. These data indicate that oligo(dT)12-18 cellulose can be used as a rapid and selective affinity column for the purification of terminal deoxynucleotidyltransferase.