Stimulatory protein kinase modulator, the cation-binding protein and megamodulin. 3. Isolation from baker's yeast.

Three peak-activity fractions of megamodulin were noted in Sephadex G-100 filtration of its crude preparation from baker's yeast (Saccharomyces cerevisiae). Megamodulin thus prepared and its Mg2+-binding complex were shown not only to augment the activity of rabbit brain megamodulin-dependent protein kinase I (M-PK1) but also to interact with arginine-rich histone.