title: Mode of action of streptozotocin.
abstract: Streptozotocin induces rapid degradation of deoxyribonucleic acid (DNA) in actively dividing or resting Bacillus subtilis cells. Difference spectroscopy showed that the antibiotic interacts specifically with cytosine containing mononucleotides in vitro. This interference occurs only within the very narrow pH range of 5 to 5.5 and is reversed immediately upon lowering or increasing the pH. No measurable interaction was observed between isolated DNA and streptozotocin. The possibility is discussed that interaction of streptozotocin with cytosine residues in cellular DNA, although possibly taking place at a very low frequency, may constitute the primary step inducing DNA strand breakage.
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001224:Aspartic Acid / Q000378:metabolism; D001412:Bacillus subtilis / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D001426:Bacterial Proteins / Q000096:biosynthesis; D002247:Carbon Isotopes; D002474:Cell-Free System; D002499:Centrifugation, Density Gradient; D055598:Chemical Phenomena; D002621:Chemistry; D003470:Culture Media; D003597:Cytosine Nucleotides; D004247:DNA / Q000378:metabolism; D004269:DNA, Bacterial / Q000096:biosynthesis / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002247:Carbon Isotopes; D003470:Culture Media; D003597:Cytosine Nucleotides; D004269:DNA, Bacterial; D001224:Aspartic Acid; D004247:DNA