Evidence for a nicotinamide nucleotide transhydrogenase in Klebsiella pneumoniae.
Bacterial membranes from Klebsiella pneumoniae were investigated for the presence of a nicotinamide nucleotide transhydrogenase activity. Inverted membrane vesicles derived from these cells catalyzed a reduction of NAD+ or 3-acetylpyridine-NAD+ by NADPH, which showed a maximal activity of about 260 nmoles/minute per milligram protein at pH 7-8. In the presence of a protonic uncoupler the specific activity was stimulated about two-fold in this pH range. The presence of detergents did not further increase the specific activity of enzyme. The Klebsiella pneumoniae transhydrogenase activity was sensitive to phenylarsine oxide and palmityl-Coenzyme A, both of which are agents known to inhibit the mammalian enzyme. The Ki-value for palmityl-Coenzyme A with respect to NADPH was about 1.25 microM. Antibodies raised against beef heart transhydrogenase crossreacted with a 54 kD protein in the Klebsiella pneumonia membrane.
Fristedt
U
U
Department of Biochemistry, Arrhenius Laboratories, University of Stockholm, Sweden.
Rydström
J
J
Persson
B
B
D000818:Animals; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D002417:Cattle; D002462:Cell Membrane / Q000201:enzymology; D003067:Coenzymes / Q000378:metabolism; D007700:Kinetics; D007711:Klebsiella pneumoniae / Q000201:enzymology*; D008929:Mitochondria, Heart / Q000201:enzymology; D009243:NAD / Q000031:analogs & derivatives / Q000378:metabolism; D009250:NADP Transhydrogenases / Q000378:metabolism*; D010084:Oxidation-Reduction; D013367:Submitochondrial Particles / Q000201:enzymology
D003067:Coenzymes; D009243:NAD; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; C005941:3-acetylpyridine adenine dinucleotide; D009250:NADP Transhydrogenases