Poly(adenosine diphosphate ribose) is covalently linked to nuclear proteins by two types of bonds.
(ADP-ribose)n residues formed by short-term incubation of adult rat liver and Ehrlich carcinoma nuclei with labeled NAD were analyzed by Cs2SO4/guanidinium chloride/urea density gradient centrifugation. Comparison with samples in which the protein had been completely digested revealed that most, or probably all, acid-insoluble (ADP-ribose)n chains are covalently bound to nuclear proteins, as is true for the short, acid-soluble (ADP-ribose)n chains. Complete release of (ADP-ribose)n chains is effected by dilute alkali. In contrast, NH2OH liberated only part of the long and the short (ADP-ribose)n residues from the protein conjugates, indicating two types of bonds, both alkali-labile, but only one susceptible to neutral hydroxylamine. Both types of bonds were equally distributed among acid-soluble and acid-insoluble (ADP-ribose)n chains. -Stability of the (ADP-ribose)n protein conjugates during isolation is only guaranteed at pH values below 7.
D000818:Animals; D002286:Carcinoma, Ehrlich Tumor / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism*; D002499:Centrifugation, Density Gradient; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008099:Liver / Q000378:metabolism; D046911:Macromolecular Substances; D009243:NAD / Q000378:metabolism; D009702:Nucleoside Diphosphate Sugars / Q000378:metabolism*; D010447:Peptide Hydrolases; D011064:Poly Adenosine Diphosphate Ribose / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D012972:Sodium Hydroxide
D046911:Macromolecular Substances; D009702:Nucleoside Diphosphate Sugars; D011506:Proteins; D009243:NAD; D011064:Poly Adenosine Diphosphate Ribose; D012972:Sodium Hydroxide; D010447:Peptide Hydrolases