Human endonuclease specific for apurinic/apyrimidinic sites in DNA. Partial purification and characterization of multiple forms from placenta.

摘要: Six chromatographically distinct forms of endonuclease active on apurinic and apyrimidinic sites in DNA have been purified away from phosphatases, N-glycosidases, other DNases human placenta. The seem to be monomeric proteins 27,000 31,000 daltons, although catalytically similar, they can distinguished one another the basis substrate Km effects small molecules such as ATP. Analysis enzymatic activity a spectrum damaged substrates indicates that enzyme probably act at an appreciable rate only adjacent phosphodiester bond deoxyribose lacking base (purine or pyrimidine) duplex DNA; formed by treating with acid, alkylating agents, and, probably, x-rays OsO4. incision is made so form 5'-phosphate 3'-hydroxynucleotide.