CASEIN KINASE-ACTIVITY DURING EARLY DEVEL OPMENT OF LOACH (MISGURNUS-FOSSILIS L.)

In the course of embryonic development of the leach, from the 8-cell s tage to the stage before hatching, the total casein kinase activity of cell extracts increased more than twice. Both casein kinase II (CK II ) and casein kinase I (CK I) were present in the embryos. Part of CK I I was in masked (inactive) state and the ratio of masked to unmasked f orms of the enzyme increased during embryogenesis. A part of unmasked CK II was incorporated in macromolecular complexes, that prevent its i nhibition by heparin but allow its catalytic function, The proportion of CK II not interacting with heparin increased by the end of embryoge nesis. Chromatography of cell extracts of DEAE-sorbite removes the fac tors protecting CK II against inhibition by heparin.