PARTIAL-PURIFICATION AND CHARACTERIZATION OF A PROTEIN LYSINE METHYLTRANSFERASE FROM PLASMODIA OF PHYSARUM-POLYCEPHALUM

Plasmodia of Physarum polycephalum have an active protein lysine methyltransferase (S-adenosyl-methionine:protein-lysine methyltransferase, EC 2.1.1.43). This enzyme has been purified 40-fold with a 13% yield, and it catalyzes the transfer of methyl groups from S-adenosyl-L-methionine to the Є-amino group of lysine residues with formation of NЄ -mono-, NЄ-di-, and NЄ-timethyllysines in a molar ratio of 4:1:1 based on [14C] methyl incorporation into the methylated lysines. The ratio remains unchanged at all stages of the partial purification, as well as after fractionation by sucrose density gradient centrifugation and gel electrophoresis. © 1979, American Chemical Society. All rights reserved.