DNA-HYDROLYZING AND RNA-HYDROLYZING ANTIBODIES IN HUMAN-MILK AND THEIR POSSIBLE BIOLOGICAL ROLE

Fractions of class G immunoglobulins (IgG) and their Fab and F(ab)(2) fragments from the milk of healthy mothers were purified by chromatogr aphy on consecutively protein A Sepharose, DEAE-cellulose, Toyopear1 H W-55, and DNA-cellulose, and were shown to hydrolyze DNA and RNA. The ability to hydrolyze nucleic acids was proved to be a natural property of IgG, determined by their light chains. Human milk abzymes differed in their substrate specificity from eukaryotic DNases, pancreatic RNa se A, other human RNases, and serum IgG abzymes from patients with aut oimmune diseases. It was assumed that milk abzymes can degrade viral a nd bacterial nucleic acids, thus playing an important role in baby pro tection mechanisms.