Jf. Glickman et al., PURIFICATION AND CHARACTERIZATION OF RECOMBINANT BACULOVIRUS-EXPRESSED MOUSE DNA METHYLTRANSFERASE, Biochemical and biophysical research communications, 230(2), 1997, pp. 280-284
DNA methylation is essential for normal embryonic development in mice.
An understanding of how DNA methylation is controlled is largely depe
ndent upon the isolation and characterization of the cellular componen
ts of the DNA methylation system. The enzyme which methylates DNA in e
ukaryotic cells is a C-5 cytosine DNA methyltransferase. Historically,
the characterization of this enzyme has been limited by its availabil
ity and purity. Here, we present a single-step purification of 4 mg of
baculovirus-expressed mouse DNA methyltransferase containing a nickel
-affinity leader peptide. The recombinant DNA methyltransferase co-pur
ified with inhibitory RNA which was removed by treatment with ribonucl
ease A. Like its non-recombinant counterpart, the recombinant enzyme i
s activated by hemi-methylation. A direct steady-state kinetic compari
son between the recombinant baculovirus-expressed enzyme with its MEL
cell-derived counterpart is presented. (C) 1997 Academic Press