Abstract
SummaryThe nature of the 3H activity released from M. radiodurans after γ-ray doses of 500 krads which cause no decrease in cellular viability has been investigated by gel filtration and alkaline sucrose-gradient centrifugation. Immediately after irradiation, oligonucleotides ∼7·0 × 105 daltons are released which are subsequently rapidly degraded in broth to thymine by exonucleolytic enzymes. Such enzymes are also capable of degrading mammalian DNA. Treatment with iodoacetamide 2 × 10−5 M results in a sensitization expressed as a loss of the shoulder of the dose-response curve. The study of DNA degradation products in M. radiodurans treated with iodoacetamide suggests that sensitization is due to inhibition of an enzyme which excises DNA from a DNA-membrane complex. Iodoacetamide appears not to inhibit the removal of thymine from irradiated DNA. The results suggest that at least two enzymes are involved in the repair of γ-ray damage in M. radiourans and that repair of the DNA-membrane complex is mainly re...
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: International journal of radiation biology and related studies in physics, chemistry, and medicine
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
