Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0519030 (Klebsiella)
 21,988 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Arylamine N-acetyltransferase (NAT) activities with 2-aminofluorene (2-AF) were determined in the bacterium Klebsiella pneumoniae. Cytosols or suspensions of K. pneumoniae with or without specific concentrations of diallyl sulphide (DAS) or diallyl disulphide (DADS) as co-treatment showed different percentages of 2-AF acetylation. The data indicated that there was decreased NAT activity associated with increased levels of DAS or DADS in K. pneumoniae. In growth studies on K. pneumoniae it was demonstrated that DAS or DADS elicited a dose-dependent bacteriocide effect on K. pneumoniae. For the cytosol examinations, the apparent values of Km and Vmax were 0.96+/-0.09 mM and 7.87+/-0.79 nmol min(-1) mg(-1) protein, respectively, for 2-AF. However, when DAS or DADS was added to the reaction mixtures, the apparent values of Km and Vmax were 0.16+/-0.04 mM and 0.99+/-0.16 nmol min(-1) mg(-1) protein with DAS, respectively, and 0.14+/-0.18 mM and 0.85+/-0.10 nmol min(-1) mg(-1) protein with DADS, respectively, for 2-AF. For the intact bacteria examination, the apparent values of Km and Vmax were 0.57+/-0.06 mM and 2.00+/-0.14 nmol min(-1) per 10x10(10) CFU, respectively, for 2-AF. However, when DAS or DADS was added to the reaction mixtures, the apparent of values of Km and Vmax were 0.41+/-0.04 mM and 1.30+/-0.10 nmol min(-1) per 10x10(10) CFU with DAS, respectively, and 0.34+/-0.04 mM and 1.08+/-0.08 nmol min(-1) per 10x10(10) CFU with DADS, respectively, for 2-AF. This report is the first demonstration to show that the garlic components DAS and DADS would affect K. pneumoniae growth and NAT activity.
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PMID:Effects of the garlic compounds diallyl sulphide and diallyl disulphide on arylamine N-acetyltransferase activity in Klebsiella pneumoniae. 1021 79

Arylamine N-acetyltransferase activity has been described in various bacterial species. Bacterial N-acetyltransferases, including those from bacteria of the gut flora, may be involved in the metabolism of xenobiotics, thereby exerting physiopathological effects. We characterized these enzymes further by steady-state kinetics, time-dependent inhibition, and DNA hybridization in 40 species, mostly from the human intestinal microflora. We report for the first time N-acetyltransferase activity in 11 species of Proteobacteriaceae from seven genera: Citrobacter amalonaticus, Citrobacter farmeri, Citrobacter freundii, Klebsiella ozaenae, Klebsiella oxytoca, Klebsiella rhinoscleromatis, Morganella morganii, Serratia marcescens, Shigella flexneri, Plesiomonas shigelloides, and Vibrio cholerae. We estimated apparent kinetic parameters and found that 5-aminosalicylic acid, a compound efficient in the treatment of inflammatory bowel diseases, was acetylated with a catalytic efficiency 27 to 645 times higher than that for its isomer, 4-aminosalicylic acid. In contrast, para-aminobenzoic acid, a folate precursor in bacteria, was poorly acetylated. Of the wild-type strains studied, Pseudomonas aeruginosa was the best acetylator in terms of both substrate spectrum and catalytic efficiency. DNA hybridization with a Salmonella enterica serovar Typhimurium-derived probe suggested the presence of this enzyme in eight proteobacterial and four gram-positive species. Molecular aspects together with the kinetic data suggest distinct functional features for this class of microbial enzymes.
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PMID:Identification and functional characterization of arylamine N-acetyltransferases in eubacteria: evidence for highly selective acetylation of 5-aminosalicylic acid. 1134 50

Arylamine N-acetyltransferase (NAT) enzymes have been found in laboratory animals, humans, microorganisms (fungi, bacteria and parasites), and in plants. But the characteristics of NAT from Klebsiella pneumoniae are not clear. NAT activities with p-aminobenzoic acid (PABA) and 2-aminofluorene (AF) as substrates were examined in the cytosol of K. pneumoniae. NAT activity (N-acetylation of substrates) was determined using an acetyl coenzyme A recycling assay and high performance liquid chromatography for determining the amounts of acetylated or non-acetylated PABA or AF. NAT activities from a number of K. pneumoniae isolates were found to be 0.72 +/- 0.08 nmol/min/mg protein for AF, and 0.49 +/- 0.04 nmol/min/mg protein for PABA. The kinetic parameters of apparent Michaelis constant (Km) and maximum velocity (Vmax) obtained were 2.92 +/- 0.48 mM and 7.89 +/- 0.82 nmol/min/mg protein, respectively, for AF and 2.42 +/- 0.28 mM and 9.87 +/- 0.64 nmol/min/mg protein, respectively, for PABA. The optimal pH value for the NAT activity was 7.0 for AF and PABA. The optimal temperature for NAT activity was 37 degrees C for both substrates. The NAT activity was inhibited by 50% with 0.25 mM iodoacetamide, and by more than 90% at 1.0 mM. Among a series of divalent cations and salts, Cu2+ and Zn2+ were the most potent inhibitors of NAT activity.
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PMID:Evidence for arylamine N-acetyltransferase activity in Klebsiella pneumoniae. 1534 Jun 47