[Regenerating hematopoietic tissue as a source for a low molecular weight factor that inhibits leukemic cell...

Using a successive set of chromatographic methods, a low molecular weight factor inhibiting leukemic cells proliferation has been isolated from an aqueous extract of regenerating hematopoietic tissue. This factor inhibits DNA synthesis in leukemic cells about 1000-fold more effectively than the original extract. The factor activity does not change after treatment by proteinase K; however, successive action of endo-alpha-N-acetylgalactose aminidase and proteinase K significantly decreases the efficiency of the factor action. This factor whose molecular mass is less than 3 kDa seems to be of glycopeptide origin.