23 research outputs found

    The high school student in the school district spase and inner school space:one understanding through the questionnaire

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    textabstractA novel papain inhibitory protein (SPI) from Streptomyces mobaraensis was studied to measure its inhibitory effect on bacterial cysteine protease activity (Staphylococcus aureus SspB) and culture supernatants (Porphyromonas gingivalis, Bacillus anthracis). Further, growth of Bacillus anthracis, Staphylococcus aureus, Pseudomonas aeruginosa, and Vibrio cholerae was completely inhibited by 10 μM SPI. At this concentration of SPI, no cytotoxicity was observed. We conclude that SPI inhibits bacterial virulence factors and has the potential to become a novel therapeutic treatment against a range of unrelated pathogenic bacteria. Copyrigh

    Significance of Cuscutain, a cysteine protease from Cuscuta reflexa, in host-parasite interactions

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    <p>Abstract</p> <p>Background</p> <p>Plant infestation with parasitic weeds like <it>Cuscuta reflexa </it>induces morphological as well as biochemical changes in the host and the parasite. These modifications could be caused by a change in protein or gene activity. Using a comparative macroarray approach <it>Cuscuta </it>genes specifically upregulated at the host attachment site were identified.</p> <p>Results</p> <p>One of the infestation specific <it>Cuscuta </it>genes encodes a cysteine protease. The protein and its intrinsic inhibitory peptide were heterologously expressed, purified and biochemically characterized. The haustoria specific enzyme was named cuscutain in accordance with similar proteins from other plants, e.g. papaya. The role of cuscutain and its inhibitor during the host parasite interaction was studied by external application of an inhibitor suspension, which induced a significant reduction of successful infection events.</p> <p>Conclusions</p> <p>The study provides new information about molecular events during the parasitic plant - host interaction. Inhibition of cuscutain cysteine proteinase could provide means for antagonizing parasitic plants.</p

    Features of the transglutaminase-activating metalloprotease from Streptomyces mobaraensis DSM 40847 produced in Escherichia coli.

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    Transglutaminase from Streptomyces mobaraensis (MTG) is an important enzyme for numerous industrial applications. Recombinant production requires proteolytic activation of the zymogen. The study provides a convenient procedure for the preparation of the transglutaminase-activating metalloprotease (TAMP) in Escherichia coli. In contrast to wtTAMP, rTAMP exhibited the P domain of convertases as molecular mass of 55.7 kDa suggested. Protein integrity was beneficially influenced by 2-5 mM CaCl. Study of pH and temperature optima assigned rTAMP to the neutral metalloproteases, more heat-resistant than Dispase but not thermolysin. Zinc had no inhibiting effect but 3.1 µM EDTA completely reduced activity of 5 nM TAMP. MTG, exceeding concentration of rTAMP by three orders of magnitude, was largely activated within few minutes. The kinetic parameters K (1.31 ± 0.05 mM) and k (135 ± 4.3 s), monitored by isothermal titration calorimetry (ITC), further highlighted catalytic efficiency (103,053 M s) of rTAMP and rapid processing of MTG. ITC even revealed that inhibition of rTAMP by its intrinsic inhibitory protein SSTI was an enthalpy-driven process resulting in K of 199 ± 37.9 nM. The production procedure of rTAMP in E. coli closes the gap between production and application of recombinant MTG and may enhance relevance of MTG-mediated reactions in pharmaceutical processes

    The N-terminal peptide of the transglutaminase-activating metalloprotease inhibitor from Streptomyces mobaraensis accommodates both inhibition and glutamine cross-linking sites.

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    Streptomyces mobaraensis is a key player for the industrial production of the protein cross-linking enzyme microbial transglutaminase (MTG). Extra-cellular activation of MTG by the transglutaminase-activating metalloprotease (TAMP) is regulated by the TAMP inhibitory protein SSTI that belongs to the large Streptomyces subtilisin inhibitor (SSI) family. Despite decades of SSI research, the binding site for metalloproteases such as TAMP remained elusive in most of the SSI proteins. Moreover, SSTI is a MTG substrate, and the preferred glutamine residues for SSTI cross-linking are not determined. To address both issues, i. e. determination of the TAMP and the MTG glutamine binding sites, SSTI was modified by distinct point mutations as well as elongation or truncation of the N-terminal peptide by six and three residues, respectively. Structural integrity of the mutants was verified by determination of protein melting points and supported by unimpaired subtilisin inhibitory activity. While exchange of single amino acids could not disrupt decisively the SSTI TAMP interaction, the N-terminally shortened variants clearly indicated the highly conserved Leu40-Tyr41 as binding motif for TAMP. Moreover, enzymatic biotinylation revealed that an adjacent glutamine pair, upstream from Leu40-Tyr41 in the SSTI precursor protein, is the preferred binding site of MTG. This extension peptide disturbs the interaction with TAMP. The structure of SSTI was furthermore determined by X-ray crystallography. While no structural data could be obtained for the N-terminal peptide due to flexibility, the core structure starting from Tyr41 could be determined and analyzed, which superposes well with SSI-family proteins. This article is protected by copyright. All rights reserved

    The N‐terminal peptide of the transglutaminase‐activating metalloprotease inhibitor from Streptomyces mobaraensis accommodates both inhibition and glutamine cross‐linking sites

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    Streptomyces mobaraensis is a key player for the industrial production of the protein cross‐linking enzyme microbial transglutaminase (MTG). Extra‐cellular activation of MTG by the transglutaminase‐activating metalloprotease (TAMP) is regulated by the TAMP inhibitory protein SSTI that belongs to the large Streptomyces subtilisin inhibitor (SSI) family. Despite decades of SSI research, the binding site for metalloproteases such as TAMP remained elusive in most of the SSI proteins. Moreover, SSTI is a MTG substrate, and the preferred glutamine residues for SSTI cross‐linking are not determined. To address both issues, that is, determination of the TAMP and the MTG glutamine binding sites, SSTI was modified by distinct point mutations as well as elongation or truncation of the N‐terminal peptide by six and three residues respectively. Structural integrity of the mutants was verified by the determination of protein melting points and supported by unimpaired subtilisin inhibitory activity. While exchange of single amino acids could not disrupt decisively the SSTI TAMP interaction, the N‐terminally shortened variants clearly indicated the highly conserved Leu40‐Tyr41 as binding motif for TAMP. Moreover, enzymatic biotinylation revealed that an adjacent glutamine pair, upstream from Leu40‐Tyr41 in the SSTI precursor protein, is the preferred binding site of MTG. This extension peptide disturbs the interaction with TAMP. The structure of SSTI was furthermore determined by X‐ray crystallography. While no structural data could be obtained for the N‐terminal peptide due to flexibility, the core structure starting from Tyr41 could be determined and analysed, which superposes well with SSI‐family proteins

    Involvement of a Novel Class C Beta-Lactamase in the Transglutaminase Mediated Cross-Linking Cascade of Streptomyces mobaraensis DSM 40847.

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    Streptomyces mobaraensis DSM 40847 secretes transglutaminase that cross-links proteins via γ-glutamyl-ε-lysine isopeptide bonds. Characterized substrates are inhibitory proteins acting against various serine, cysteine and metalloproteases. In the present study, the bacterial secretome was examined to uncover additional transglutaminase substrates. Fractional ethanol precipitation of the exported proteins at various times of culture growth, electrophoresis of the precipitated proteins, and sequencing of a 39 kDa protein by mass spectrometry revealed the novel beta-lactamase Sml-1. As indicated by biotinylated probes, Sml-1, produced in E. coli, exhibits glutamine and lysine residues accessible for transglutaminase. The chromogenic cephalosporin analogue, nitrocefin, was hydrolyzed by Sml-1 with low velocity. The obtained Km and kcat values of the recombinant enzyme were 94.3±1.8 μM and 0.39±0.03 s-1, respectively. Penicillin G and ampicillin proved to be weak inhibitors of nitrocefin hydrolysis (Ki of 0.1 mM and 0.18 mM). Negligible influence of metals on β-lactamase activity ruled out that Sml-1 is a Zn2+-dependent class B beta-lactamase. Rather, sequence motifs such as SITK, YSN, and HDG forming the active core in a hypothetical structure may be typical for class C beta-lactamases. Based on the results, we assume that the novel transglutaminase substrate ensures undisturbed growth of aerial hyphae in Streptomyces mobaraensis by trapping and inactivating hostile beta-lactam antibiotics

    Decoding the Papain Inhibitor from Streptomyces mobaraensis as Being Hydroxylated Chymostatin Derivatives: Purification, Structure Analysis, and Putative Biosynthetic Pathway.

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    produces the papain inhibitor SPI consisting of a 12 kDa protein and small active compounds (SPI). Purification of the papain inhibitory compounds resulted in four diverse chymostatin derivatives that were characterized by NMR and MS analysis. Chymostatins are hydrophobic tetrapeptide aldehydes from streptomycetes, e.g., and , that reverse chymosin-mediated angiotensin activation and inhibit other serine and cysteine proteases. Chymotrypsin and papain were both inhibited by the SPI compounds in the low nanomolar range. SPI differs from the characterized chymostatins by the exchange of phenylalanine for tyrosine. The crystal structure of one of these chymostatin variants confirmed its molecular structure and revealed a S-configured hemithioacetal bond with the catalytic Cys25 thiolate as well as close interactions with hydrophobic S1 and S2 subsite amino acids. A model for chymostatin biosynthesis is provided based on the discovery of clustered genes encoding several putative nonribosomal peptide synthetases; among them, there is the unusual CstF enzyme that accommodates two canonical amino acid activation domains as well as three peptide carrier protein domains

    Structure of the Dispase Autolysis-inducing Protein from Streptomyces mobaraensis and Glutamine Cross-linking Sites for Transglutaminase.

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    Transglutaminase from Streptomyces mobaraensis (MTG) is an important enzyme for cross-linking and modifying proteins. An intrinsic substrate of MTG is the dispase autolysis-inducing protein (DAIP). The amino acid sequence of DAIP contains 5 potential glutamines and 10 lysines for MTG-mediated cross-linking. The aim of the study was to determine the structure and glutamine cross-linking sites of the first physiological MTG substrate. A production procedure was established in Escherichia coli BL21 (DE3) to obtain high yields of recombinant DAIP. DAIP variants were prepared by replacing four of five glutamines for asparagines in various combinations via site-directed mutagenesis. Incorporation of biotin cadaverine revealed a preference of MTG for the DAIP glutamines in the order of Gln-39 ≫ Gln-298 > Gln-345 ∼ Gln-65 ≫ Gln-144. In the structure of DAIP the preferred glutamines do cluster at the top of the seven-bladed β-propeller. This suggests a targeted cross-linking of DAIP by MTG that may occur after self-assembly in the bacterial cell wall. Based on our biochemical and structural data of the first physiological MTG substrate, we further provide novel insight into determinants of MTG-mediated modification, specificity, and efficiency
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