title: ADP-ribosylation of nuclear proteins in normal lymphocytes and in low-grade malignant non-Hodgkin lymphoma cells.
abstract: Normal lymphocytes and lymphocytes from patients with low-grade malignant non-Hodgkin lymphoma were isolated from blood by a Percoll gradient procedure. Absence of cell proliferation in both cell types was indicated by very low [3H]thymidine incorporation rates. Determination of endogenous protein-bound single ADP-ribose residues by a radioimmunoassay revealed that the leukemic cells had 2.5-times lower levels of the NH2OH-sensitive and a 4-fold lower amount of NH2OH-resistant ADP-ribose . protein conjugate subfractions, respectively, than normal lymphocytes. By contrast, "total" ADP-ribose transferase activity, as measured in homogenates or permeabilized cells in the presence of DNase, was two-times higher in leukemic cells, whereas activity determined in permeabilized cells in the absence of added DNase was practically identical in both cell types. The apparent discrepancy between ADP-ribose transferase activity and endogenous levels of protein-bound single ADP-ribose residues may be explained in part by an enzyme inhibitor present in normal human lymphocytes. NAD + NADH levels were decreased 2.5-fold in the leukemic cells. This decrease, however, does not explain the reduced levels of mono(ADP-ribose) . protein conjugates since the ratio of protein-bound single ADP-ribose residues to NAD is distinctly different in leukemic lymphocytes compared to normal lymphocytes.
mesh_terms: D036002:ADP Ribose Transferases; D000246:Adenosine Diphosphate Ribose / Q000378:metabolism*; D001402:B-Lymphocytes / Q000378:metabolism; D004261:DNA Replication; D006801:Humans; D007700:Kinetics; D007945:Leukemia, Lymphoid / Q000378:metabolism*; D008214:Lymphocytes / Q000378:metabolism*; D008223:Lymphoma / Q000378:metabolism*; D009243:NAD / Q000378:metabolism; D009698:Nucleoproteins / Q000378:metabolism*; D009702:Nucleoside Diphosphate Sugars / Q000378:metabolism*; D009713:Nucleotidyltransferases / Q000378:metabolism; D011065:Poly(ADP-ribose) Polymerases; D012016:Reference Values; D013936:Thymidine / Q000378:metabolism
chemical_list: D009698:Nucleoproteins; D009702:Nucleoside Diphosphate Sugars; D009243:NAD; D000246:Adenosine Diphosphate Ribose; D036002:ADP Ribose Transferases; D011065:Poly(ADP-ribose) Polymerases; D009713:Nucleotidyltransferases; D013936:Thymidine