Inhibition of DNA synthesis in permeabilized mouse P815 mast cells by arabinofuranosyladenine 5'-triphosphate.
P815 mast cells (mouse leukemic cells) have been successfully permeabilized to 9-beta-arabinofuranosyladenine 5'-triphosphate (araATP) using lysolecithin. The permeabilized cells remained viable according to the following criteria: (a) exclusion of trypan blue after replacing the lysolecithin with culture medium; (b) cell growth rate identical to control cultures, and (c) intact DNA-synthesizing complex in permeable cells. It was shown that permeabilized cells incorporate [3H]thymidine and [3H]deoxyadenosine-triphosphate (dATP) into DNA when the suspension is supplied with the appropriate substrates and cofactors. Permeable cells break down araATP to 9-beta-D-arabinofuranosyladenine 5'-diphosphate only slightly after incubation for 60 min; no further dephosphorylation to 9-beta-D-arabinofuranosyladenine 5'-monophosphate or 9-beta-D-arabinofuranosyladenine occurs. In kinetic experiments it was shown that the DNA-replicating complex of permeabilized cells is competitively inhibited by araATP with respect to dATP; Ki(araATP) was determined to be 0.6 microM and the Km(dATP), 0.9 microM.
D000818:Animals; D001088:Arabinonucleotides / Q000494:pharmacology*; D002463:Cell Membrane Permeability / Q000187:drug effects; D002478:Cells, Cultured; D004261:DNA Replication; D004273:DNA, Neoplasm / Q000096:biosynthesis*; D005057:Eukaryotic Cells / Q000378:metabolism; D007942:Leukemia, Experimental / Q000378:metabolism*; D008244:Lysophosphatidylcholines / Q000494:pharmacology; D008407:Mast Cells / Q000378:metabolism*; D051379:Mice; D001084:Vidarabine Phosphate / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology*
D001088:Arabinonucleotides; D004273:DNA, Neoplasm; D008244:Lysophosphatidylcholines; D001084:Vidarabine Phosphate; C000101:ara-ATP