抄録
Mouse myeloid leukemia (Ml) cells that were induced to differentiate with dexamethasone showed at least a 100-fold increase in lysozyme activity. This induced activity was distributed in various subcellular fractions, the molecular weights of which were nearly identical. The activity detected in the nuclear fraction (nearly one-third that of the total number of cells) could be extracted completely with 0.3 M NaCl or 0.4 N H2SO4, but not with 0.74 M perchloric acid. When nuclei were incubated with DNase I or micrococcal nuclease, the release of lysozyme showed a positive relation to increased digestion of DNA. The lysozyme, released by treatment with micrococcal nuclease, was distributed throughout the region of the multimers of nucleosomes after centrifugation on a 5-20 % linear sucrose gradient. Our results suggest that a part of the lysozyme activity induced during M1 cell differentiation may be associated with chromatin DNA.
