Localization of deoxyribonucleic acid-stimulated adenosine triphosphatases in human lymphocytes

Two enzymes hydrolyzing ATP (ATPase A and ATPase B) were purified from freshly isolated lymphocytes of human tonsils. Both enzymes are stimulated by single-stranded DNA and seem to be localized in the chromatin. ATPase A and ATPase B appear to be distinct enzymes as judged from their elution profiles obtained after DEAE-cellulose and ATP-Sepharose column chromatography, from their behavior towards actinomycin D, a DNA intercalating agent, and from their sensitivity to monovalent salt concentration.