Modulation of glyceraldehyde-3-phosphate dehydrogenase in Salmonella abortus equi lipopolysaccharide-treated mice.
Nitric oxide (NO) is known to inhibit glyceraldehyde-3-phosphate dehydrogenase enzyme activity caused by an NAD(+)-dependent posttranslational protein modification mechanism. In order to study a possible similar protein modification under in vivo conditions, mice were injected with bacterial endotoxin known to endogenously generate NO. In endotoxin-treated mice glyceraldehyde-3-phosphate dehydrogenase enzyme activity was significantly reduced in cytosolic fractions of heart and spleen, compared to 100,000 x g supernatants of untreated control animals. Enzyme activity was unaffected in lung and kidney cytosol of the endotoxin-treated group. Employing the differential NAD(+)-dependent labelling method, glyceraldehyde-3-phosphate dehydrogenase in heart and spleen cytosol of the endotoxin-treated group, versus the control group, had been endogenously modified. These changes were not observed in lung and kidney cytosol of endotoxin-challenged animals. Using Western blot analysis no significant changes in the amount of protein (glyceraldehyde-3-phosphate dehydrogenase) in control versus endotoxin-treated animals was detectable. Since an endogenously NAD(+)-modified glyceraldehyde-3-phosphate dehydrogenase occurred in endotoxin-treated mice, at least in some organs, this NO-stimulated posttranslational protein modification mechanism seems to function under in vivo conditions. A covalent protein modification mechanism, rather than differences in the amount of the protein is likely to cause changes in enzyme activity.
Dimmeler
S
S
Faculty of Biology, Department of Biological Chemistry, University of Konstanz, Germany.
Messmer
U K
UK
Tiegs
G
G
Brüne
B
B
D000818:Animals; D015153:Blotting, Western; D004731:Endotoxins / Q000494:pharmacology*; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000032:analysis / Q000187:drug effects*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009243:NAD / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism; D012475:Salmonella; D014115:Toxemia / Q000201:enzymology* / Q000378:metabolism
D004731:Endotoxins; D008070:Lipopolysaccharides; D009243:NAD; D009569:Nitric Oxide; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases