Publications

• Purification and some properties of carboxynorspermidine synthase participating in a novel biosynthetic pathway for norspermidine in Vibrio alginolyticus.

  Nakao H., Shinoda S., Yamamoto S.

  Carboxynorspermidine synthase, mediates the nicotinamide-nucleotide-linked reduction of the Schiff base H2N(CH2)3N = CHCH2CH(NH2)COOH. This is formed from L-aspartic beta-semialdehyde (ASA) and 1,3-diaminopropane (DAP) and is reduced to carboxynorspermidine [H2N(CH2)3NH(CH2)2CH(NH2)COOH], an inter ... >> More

  Carboxynorspermidine synthase, mediates the nicotinamide-nucleotide-linked reduction of the Schiff base H2N(CH2)3N = CHCH2CH(NH2)COOH. This is formed from L-aspartic beta-semialdehyde (ASA) and 1,3-diaminopropane (DAP) and is reduced to carboxynorspermidine [H2N(CH2)3NH(CH2)2CH(NH2)COOH], an intermediate in the novel pathway for norspermidine (NSPD) biosynthesis. The enzyme was purified to apparent homogeneity from Vibrio alginolyticus and characterized. The overall purification was about 1800-fold over the crude extract, with a yield of 33%. The enzyme displayed an apparent Mr of 93500 +/-1000 by gel filtration and 45100 +/-500 by SDS-PAGE, indicating that the native form is probably composed of two subunits of similar size. The specific activity of the purified enzyme was 31.0 mumol carboxynorspermidine produced min-1 (mg protein)-1. The enzyme was activated by dithiothreitol, and inhibited by SH-reactive compounds. The pH and temperature optima were 7.25-7.5 and 37 degrees C, respectively. The Km value for the Schiff base was 4.68 mM, measured by varying the ASA concentration while keeping the DAP concentration constant. Putrescine was slightly active as a substrate, forming carboxyspermidine (at about 7% of the rate of DAP), but ethylenediamine, cadaverine and D-ASA were inert. The Km value for NADPH was 1.51 mM. NADH was a much poorer cofactor than NADPH. When V. alginolyticus was grown in the presence of 5 mM-NSPD, the specific activity of this enzyme was reduced by approximately 70%. NSPD also repressed two other enzymes responsible for its biosynthesis, 2,4-diaminobutyrate decarboxylase and carboxynorspermidine decarboxylase. << Less

  J. Gen. Microbiol. 137:1737-1742(1991) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• An alternative polyamine biosynthetic pathway is widespread in bacteria and essential for biofilm formation in Vibrio cholerae.

  Lee J., Sperandio V., Frantz D.E., Longgood J., Camilli A., Phillips M.A., Michael A.J.

  Polyamines are small organic cations found in all cells, and the biosynthetic pathway is well described in eukaryotes and Escherichia coli. The characterized pathway uses decarboxylated S-adenosylmethionine as the aminopropyl group donor to form spermidine from putrescine by the key enzymes S-aden ... >> More

  Polyamines are small organic cations found in all cells, and the biosynthetic pathway is well described in eukaryotes and Escherichia coli. The characterized pathway uses decarboxylated S-adenosylmethionine as the aminopropyl group donor to form spermidine from putrescine by the key enzymes S-adenosylmethionine decarboxylase and spermidine synthase. We report here the in vivo characterization of an alternative polyamine biosynthetic pathway from Vibrio cholerae, the causative agent of human cholera. The pathway uses aspartate beta-semialdehyde as the aminopropyl group donor and consists of a fused protein containing l-2,4-diaminobutyrate aminotransferase and l-2,4-diaminobutyrate decarboxylase, a carboxynorspermidine dehydrogenase (CANSDH), and a carboxynorspermidine decarboxylase (CANSDC). We show that in V. cholerae, this pathway is required for synthesis of both sym-norspermidine and spermidine. Heterologous expression of the V. cholerae pathway in E. coli results in accumulation of the nonnative polyamines diaminopropane and sym-norspermidine. Genetic deletion of the V. cholerae CANSDC led to accumulation of carboxynorspermidine, whereas deletion of either CANSDC or the putative CANSDH led to loss of sym-norspermidine and spermidine. These results allowed unambiguous identification of the gene encoding CANSDH. Furthermore, deletion of either CANSDH or CANSDC led to a 50-60% reduction in growth rate of planktonic cells and severely reduced biofilm formation, which could be rescued by exogenously supplied sym-norspermidine but not spermidine. The pathway was not required for infectivity in a mouse model of V. cholerae infection. Notably, the alternative polyamine biosynthetic pathway is widespread in bacteria and is likely to play a previously unrecognized role in the biology of these organisms. << Less

  J. Biol. Chem. 284:9899-9907(2009) [PubMed] [EuropePMC]

  This publication is cited by 3 other entries.