Title The effect of oxygen on NAD breakdown in Salmonella typhimurium
Author Park, Uhnmee
Address Department of Genetic Engineering, the University of Suwon; Research Center for Molecular Microbiology, Seoul National University
Bibliography Journal of Microbiology, 33(3),234-238, 1995,
DOI
Key Words NAD breakdown, oxygen effect, anaerobic
Abstract The breakdown rate of NAD in Salmonella typhimurium was investigated both in aerobic and anaerobic conditions. After NAD is broken down to nicotinamide ring containing moiety, almost all the nicotinamide ring containing moiety recycles back to NAD pool. However almost none of the adenine containing moiety recycles back. We pulse-label the endogeneous NAD with [¹⁴C]-adenine and [³H]- niacin. The remaining [¹⁴C]-radioactivity in NAD pool at each time was regarded as unbroken portion of NAD, Where ad that of [³H] was served as a total amount of NAD to start with. Under aerobic condition, the half-life of NAD was around 2 hours. However, the breakdown rate was significantly reduced (around 3-5 fold) under anaerobic condition. The observation that under aerobic conditions, NAD turnover is considerably faster than under anaerobic conditions suggests that oxygen has important effect in NAD breakdown.
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