Pyrroloquinoline-quinone: a reactive oxygen species scavenger in bacteria.
Transgenic Escherichia coli expressing pyrroloquinoline-quinone (PQQ) synthase gene from Deinococcus radiodurans showed superior survival during Rose Bengal induced oxidative stress. Such cells showed significantly low levels of protein carbonylation as compared to non-transgenic control. In vitro, PQQ reacted with reactive oxygen species with rate constants comparable to other well known antioxidants, producing non-reactive molecular products. PQQ also protected plasmid DNA and proteins from the oxidative damage caused by gamma-irradiation in solution. The data suggest that radioprotective/oxidative stress protective ability of PQQ in bacteria may be consequent to scavenging of reactive oxygen species per se and induction of other free radical scavenging mechanism.
Misra
Hari S
HS
Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India. hsmisra@magnum.barc.ernet.in
Khairnar
Nivedita P
NP
Barik
Atanu
A
Indira Priyadarsini
K
K
Mohan
Hari
H
Apte
Shree K
SK
D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D004249:DNA Damage; D034301:Deinococcus / Q000201:enzymology; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D016166:Free Radical Scavengers / Q000378:metabolism*; D009097:Multienzyme Complexes / Q000235:genetics / Q000378:metabolism; D030781:Organisms, Genetically Modified; D018384:Oxidative Stress; D045542:PQQ Cofactor / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
D000975:Antioxidants; D016166:Free Radical Scavengers; D009097:Multienzyme Complexes; D017382:Reactive Oxygen Species; D011994:Recombinant Proteins; C076608:pyrroloquinoline quinone synthase complex; D045542:PQQ Cofactor