Search

Your search keyword '"Blanot, D"' showing total 204 results
Start Over Author "Blanot, D"
204 results on '"Blanot, D"'

5. The GTPase, CpgA is implicated in the deposition of the peptidoglycan sacculus in B. subtilis

Author

Absalon, C., Hamzé, K., Blanot, D., Frehel, C., Carballido-Lopez, R., Ib, Holland, Heijenoort J, Van, Sj, Séror, Institut de génétique et microbiologie [Orsay] (IGM), and Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)

Subjects
[SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2008

7. Biochemical Characterization of UDP-N-acetylmuramoyl-L-alanyl-D-glutamate: meso-2,6-diaminopimelate ligase (MurE) from Verrucomicrobium spinosum DSM 4136

Author

Boneca, IG, McGroty, SE, Pattaniyil, DT, Patin, D, Blanot, D, Ravichandran, AC, Suzuki, H, Dobson, RCJ, Savka, MA, Hudson, AO, Boneca, IG, McGroty, SE, Pattaniyil, DT, Patin, D, Blanot, D, Ravichandran, AC, Suzuki, H, Dobson, RCJ, Savka, MA, and Hudson, AO

Abstract

Verrucomicrobium spinosum is a Gram-negative bacterium that is related to bacteria from the genus Chlamydia. The bacterium is pathogenic towards Drosophila melanogaster and Caenorhabditis elegans, using a type III secretion system to facilitate pathogenicity. V. spinosum employs the recently discovered l,l-diaminopimelate aminotransferase biosynthetic pathway to generate the bacterial cell wall and protein precursors diaminopimelate and lysine. A survey of the V. spinosum genome provides evidence that the bacterium should be able to synthesize peptidoglycan de novo, since all of the necessary genes are present. The enzyme UDP-N-acetylmuramoyl-l-alanyl-d-glutamate: meso-2,6-diaminopimelate ligase (MurE) (E.C. 6.3.2.15) catalyzes a reaction in the cytoplasmic step of peptidoglycan biosynthesis by adding the third amino acid residue to the peptide stem. The murE ortholog from V. spinosum (murE Vs) was cloned and was shown to possess UDP-MurNAc-l-Ala-d-Glu:meso-2,6-diaminopimelate ligase activity in vivo using functional complementation. In vitro analysis using the purified recombinant enzyme demonstrated that MurEVs has a pH optimum of 9.6 and a magnesium optimum of 30 mM. meso-Diaminopimelate was the preferred substrate with a K m of 17 µM, when compared to other substrates that are structurally related. Sequence alignment and structural analysis using homology modeling suggest that key residues that make up the active site of the enzyme are conserved in MurEVs. Our kinetic analysis and structural model of MurEVs is consistent with other MurE enzymes from Gram-negative bacteria that have been characterized. To verify that V. spinosum incorporates diaminopimelate into its cell wall, we purified peptidoglycan from a V. spinosum culture; analysis revealed the presence of diaminopimelate, consistent with that of a bona fide peptidoglycan from Gram-negative bacteria.

Published
2013

12. New 5-Benzylidenethiazolidine-4-one Inhibitors of Bacterial MurD Ligase: Design, Synthesis, Crystal Structures, and Biological Evaluation

Author

Zidar, N., primary, Tomasic, T., additional, Sink, R., additional, Kovac, A., additional, Patin, D., additional, Blanot, D., additional, Contreras-Martel, C., additional, Dessen, A., additional, Muller-Premru, M., additional, Zega, A., additional, Gobec, S., additional, Peterlin-Masic, L., additional, and Kikelj, D., additional

Published
2011
Full Text
View/download PDF

23. Crystal structure of MurD ligase in complex with UMA and ADP

Author

Kotnik, M., primary, Humljan, J., additional, Contreras-Martel, C., additional, Oblak, M., additional, Kristan, K., additional, Herve, M., additional, Blanot, D., additional, Urleb, U., additional, Gobec, S., additional, Dessen, A., additional, and Solmajer, T., additional

Published
2007
Full Text
View/download PDF

34. Prolongation of murine skin grafts by FTS and its synthetic analogues.

Author

Kaiserlian, Dominique, Dujic, A., Dardenne, Mireille, Bach, J.F., Blanot, D., and Bricas, E.

Subjects
PLANT propagation, BLOOD plasma, TRANSPLANTATION immunology, T cells, BLOOD proteins, SERUM
Abstract

Synthetic serum thymic factor (FTS) and several of its analogues have been examined for immunoregulatory properties in a murine skin graft rejection model, including a syngeneic male-to-female system and an allogeneic system. In the syngeneic system control animals with and without placebo had a mean graft survival time of 29 ± 2 and 24 ± 2 days respectively. Administration of FTS [10 ng bound to a carboxymethylcellulose (CMC) vehicle three times weekly until rejection significantly delayed rejection (49 ± 3 days). Similar although less striking results were obtained across the H-2 barrier. Several FTS analogues with retarded degradation were tested in the same system without CMC. All of them were as immunosuppressive as FTS. Interesting, an analogue accelerated or delayed rejection depending on dosage indicating the multiplicity of action of thymic peptides on the various T cell subsets. [ABSTRACT FROM AUTHOR]

Published
1981

39. Incorporation of LL-diaminopimelic acid into peptidoglycan of Escherichia coli mutants lacking diaminopimelate epimerase encoded by dapF

Author

Mengin-Lecreulx, D, Michaud, C, Richaud, C, Blanot, D, and van Heijenoort, J

Abstract

Recently a dapF mutant of Escherichia coli lacking the diaminopimelate epimerase was found to have an unusual large LL-diaminopimelic acid (LL-DAP) pool as compared with that of meso-DAP (C. Richaud, W. Higgins, D. Mengin-Lecreulx, and P. Stragier, J. Bacteriol. 169:1454-1459, 1987). In this report, the consequences of high cellular LL-DAP/meso-DAP ratios on the structure and metabolism of peptidoglycan were investigated. For this purpose new efficient high-pressure liquid chromatography techniques for the separation of the DAP isomers were developed. Sacculi from dapF mutants contained a high proportion of LL-DAP that varied greatly with growth conditions. The same was observed with the two DAP-containing precursors, UDP-N-acetylmuramyl-tripeptide and UDP-N-acetylmuramyl-pentapeptide. The limiting steps for the incorporation of LL-DAP into peptidoglycan were found to be its addition to UDP-N-acetylmuramyl-L-alanyl-D-glutamate and the formation of the D-alanyl-DAP cross-bridges. The Km value of the DAP-adding enzyme for LL-DAP was 3.6 x 10(-2) M as compared with 1.1 x 10(-5) M for meso-DAP. When isolated sacculi were treated with Chalaropsis N-acetylmuramidase and the resulting soluble products were analyzed by high-pressure liquid chromatography, the proportion of the main peptidoglycan dimer was lower in the dapF mutant than in the parental strain. Moreover, the proportion of LL-DAP was higher in the main monomer than in the main dimer, where it was almost exclusively located in the donor unit. There are thus very few D-alanyl-LL-DAP cross-bridges, if any. We also observed that large amounts of LL-DAP and N-succinyl-LL-DAP were excreted in the growth medium by the dapF mutant.

Published
1988
Full Text
View/download PDF

40. Biochemical characterization of MurF from Streptococcus pneumoniae and the identification of a new MurF inhibitor through ligand-based virtual screening

Author

Turk, S., Hrast, M., Sosič, I., Barreteau, H., Mengin-Lecreulx, D., Blanot, D., and Stanislav Gobec

Abstract

MurF is an essential bacterial enzyme that is involved in the last intracellular stage of peptidoglycan biosynthesis, and therefore it has the potential to be exploited as a target for the development of new antibacterials. Here, we report on the expression, purification and biochemical characterization of MurF from an important pathogen, Streptococcus pneumoniae. Additionally, ligand-based virtual screening was successfully used and a new hit compound with micromolar inhibitory activities against MurF enzymes from S. pneumoniae and Escherichia coli was identified. MurF je esencialen bakterijski encim, ki sodeluje pri zadnji znotrajcelični stopnji biosinteze peptidoglikana in je kot tak obetavna tarča za razvoj novihprotibakterijskih učinkovin. V tem prispevku poročamo o uspešni ekspresiji, izolaciji in biokemijski karakterizaciji encima MurF iz pomembnega patogenega seva Streptococcus pneumoniae. Poleg tega smo tudi uspešno uporabili virtualno rešetanje na osnovi liganda in odkrili novo spojino zadetek z zaviralno aktivnostjo v mikromolarnem območju na encima MurFiz S. pneumoniae in Escherichia coli.

41. Design and synthesis of new peptidomimetics as potential inhibitors of MurE

Author

Živec, M., Turk, S., Blanot, D., and Stanislav Gobec

Abstract

With the continuing emergence and spread of multidrug-resistant bacteria, there is an urgent need for the development of new antimicrobial agents. One possible source of new antibacterial targets is the biosynthesis of the bacterial cellwall peptidoglycan. The assembly of the peptide stem is carried out by four essential enzymes, known as the Mur ligases (MurC, D, E and F). We have designed and synthesised a focused library of compounds as potential inhibitors of UDP-N-acetylmuramoyl-L-alanyl-D-glutamate:L-lysine ligase (MurE) from Staphylococcus aureus. This was achieved using two approaches: (i) synthesis of transition-state analogues based on the methyleneamino core; and (ii) synthesis of MurE reaction product analogues. Two methyleneamino-based compounds are identified as initial hits for inhibitors of MurE. Zaradi pojavljanja in širjenja bakterijskih sevov, ki so hkrati odporni na več vrst protimikrobnih učinkovin, obstaja velika potreba po razvoju novih zdravilnih učinkovin. Eden izmed pomembnih virov novih tarč za razvoj protimikrobnih učinkovin je biosinteza bakterijskega peptidoglikana. Biosintezo peptidne verige v peptidoglikanu katalizirajo encimi ligaze Mur (C,D, E in F), ki so nujni za bakterijsko preživetje. Načrtovali in sintetizirali smo serijo spojin kot potencialnih inhibitorjev UDP-N-acetilmuramoil-L-alanil-D-glutamat:L-lizin ligaze (MurE) iz Staphylococcus aureus. Pri tem smo uporabili dva pristopa: (i) sintezo metilenaminskih derivatov kot mimetikov prehodnega stanja in (ii) sintezo produktnih ananlogov reakcije MurE. Dve spojini z metilenaminskim ogrodjem sta primerni za nadaljni razvoj inhibitorjev MurE.

42. Design, Synthesis and in vitro Biochemical Activity of Novel Amino Acid Sulfonohydrazide Inhibitors of MurC

Author

Frlan, R., Kovaš, A., Blanot, D., Stanislav Gobec, Pečar, S., and Obreza, A.

Abstract

Mur ligases are essential enzymes involved in the cytoplasmic steps of peptidoglycan synthesis which remain attractive, yet unexploited targets. In order to develop new antibacterial agents, we have designed a series of new MurC and Mur- D inhibitors bearing amino acid sulfonohydrazide moiety. The L-Leu series of this class displayed the highest enzyme inhibition with IC50 in the concentration range between 100 and 500 iM, with L-Thr, L-Pro and L-Aladerivatives being inactive. The most promising compound of the series also expressed weak antibacterial activity against S. aureus with MIC = 128 microg/mL. Ligaze Mur so esencialni encimi za bakterije, ki sodelujejo v citoplazemskih stopnjah biosinteze peptidoglikana. Predstavljajo zanimive, vendar še ne dovolj izkoriščene tarče za protimikrobne učinkovine. Z namenom priprave novih protibakterijskih učinkovin, smo načrtovali in sintetizirali serijo novih zaviralcev MurC in MurD, ki vsebujejo aminokislinski sulfonohidrazidni fragment. Predstavniki z L-Leu so najbolj zavirali oba encima in so imeli IC50vrednosti v koncentracijskem območju 100-500 microM. Derivati z L-Thr, L- Pro in L-Ala so bili praktično neaktivni. Najobetavnejša učinkovina je imela izraženo tudi šibko protibakterijsko delovanje na S. aureus z MIC = 128 microg/L

Catalog

Books, media, physical & digital resources
See catalog results