- Identification and characterization of prokaryotic dipeptidyl-peptidase 5 from porphyromonas gingivalis
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Porphyromonas gingivalis, a Gram-negative asaccharolytic anaerobe, is a major causative organism of chronic periodontitis. Because the bacterium utilizes amino acids as energy and carbon sources and incorporates them mainly as dipeptides, a wide variety of dipeptide production processes mediated by dipeptidyl-peptidases (DPPs) should be beneficial for the organism. In the present study, we identified the fourth P. gingivalis enzyme, DPP5. In a dpp4-7-11-disrupted P. gingivalis ATCC 33277, a DPP7-like activity still remained. PGN-0756 possessed an activity indistinguishable from that of the mutant, and was identified as a bacterial orthologue of fungal DPP5, because of its substrate specificity and 28.5% amino acid sequence identity with an Aspergillus fumigatus entity. P. gingivalis DPP5 was composed of 684 amino acids with a molecular mass of 77,453, and existed as a dimer while migrating at 66 kDa on SDS-PAGE. It preferred Ala and hydrophobic residues, had no activity toward Pro at the P1 position, and no preference for hydrophobic P2 residues, showed an optimal pH of 6.7 in the presence of NaCl, demonstrated Km and kcat/Km values for Lys-Ala-MCA of 688 μM and 11.02 μM-1 s-1, respectively, and was localized in the periplasm. DPP5 elaborately complemented DPP7 in liberation of dipeptides with hydrophobic P1 residues. Examinations of DPP- and gingipain gene-disrupted mutants indicated that DPP4, DPP5, DPP7, and DPP11 together with Arg- and Lys-gingipains cooperatively liberate most dipeptides from nutrient oligopeptides. This is the first study to report that DPP5 is expressed not only in eukaryotes, but also widely distributed in bacteria and archaea.
- Ohara-Nemoto, Yuko,Rouf, Shakh M. A.,Naito, Mariko,Yanase, Amie,Tetsuo, Fumi,Ono, Toshio,Kobayakawa, Takeshi,Shimoyama, Yu,Kimura, Shigenobu,Nakayama, Koji,Saiki, Keitarou,Konishi, Kiyoshi,Nemoto, Takayuki K.
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p. 5436 - 5448
(2014/03/21)
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- Lucifensin, a Novel Insect Defensin of Medicinal Maggots: Synthesis and Structural Study
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Recently, we identified a new insect defensin, named lucifensin that is secreted/excreted by the blowfly Lucilia sericata larvae into a wound as a disinfectant during the medicinal process known as maggot therapy. Here, we report the total chemical synthesis of this peptide of 40 amino acid residues and three intramolecular disulfide bridges by using three different protocols. Oxidative folding of linear peptide yielded a peptide with a pattern of disulfide bridges identical to that of native lucifensin. The synthetic lucifensin was active against Gram-positive bacteria and was not hemolytic. We synthesized three lucifensin analogues that are cyclized through one native disulfide bridge in different positions and having the remaining four cysteines substituted by alanine. Only the analogue cyclized through a Cys16-Cys36 disulfide bridge showed weak antimicrobial activity. Truncating lucifensin at the N-terminal by ten amino acid residues resulted in a drop in antimicrobial activity. Linear lucifensin having all six cysteine residues alkylated was inactive. Circular dichroism spectra measured in the presence of α-helix-promoting compounds showed different patterns for lucifensin and its analogues. Transmission electron microscopy revealed that Bacillus subtilis treatment with lucifensin induced significant changes in its envelope. Lucifensin is the key antimicrobial peptide of the green bottle fly larvae Lucilia sericata. This defensin protects the larvae when they are exposed to the infectious environment of a wound during maggot therapy and it also contributes as a disinfectant and healing factor. Three disulfide bridges keep this 40-amino-acid peptide in the specific conformation required for its antimicrobial activity.
- Cerovsky, Vaclav,Slaninova, Jirina,Fucik, Vladimir,Monincova, Lenka,Bednarova, Lucie,Malon, Petr,Stokrova, Jitka
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experimental part
p. 1352 - 1361
(2012/05/31)
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- Remedies and/or preventives for conformational diseases
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The present invention provides a therapeutic and/or prophylactic agent against conformational diseases. An object of the present invention is to provide a therapeutic and/or prophylactic agent against conformational diseases, which comprise, as an active ingredient, a neuropeptide or a pharmacologically acceptable salt thereof having neuroprotective action.
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