Chromium (VI) comutagenesis: Characterization of the interaction of K2CrO4 with azide

✍ Scribed by Lavelle, James M.

• Book ID: 102837596
• Publisher: Wiley (John Wiley & Sons)
• Year: 1986
• Weight: 722 KB
• Volume: 8
• Category: Article
• ISSN: 0192-2521
• DOI: 10.1002/em.2860080507

✦ Synopsis

In a previous report chromate potentiated the mutagenicity of sodium azide, apparently by affecting repair andor replication of DNA. Further evidence in support of such a mechanism for chromate potentiation is reported here. Chromate does not react directly with azide or its major mutagenic metabolite, azidoalanine, eliminating such reactions as possible mechanisms for potentiation. Further, azide was unable to potentiate the mutagenicity of chromate in &dmneh ryphimunum strain TA104, which is sensitive to chromate mutagenicity but not to azide. Thus, it appears that the potentiation is not due to an action of aide in modulating chromate mutagenicity. Finally, the interaction was not altered by deficiency in recA gene product in S typhimrium GW19, nor by enhancement of SOS repair in the pKh4lOl containing strain TA100. Thus, induction of recAdependent functions seems to play no role in the comutagenic actions of chromate. The simplest explanation for potentiation seems to be that chromate is able either to limit errorfree recovery from azide-induced DNA damage or to promote error-prone repair or error-prone processing at sites of lesions.