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1.
Background
Bacteriocins are very diverse group of antimicrobial peptides produced by a wide range of bacteria and known for their inhibitory activity against various human and animal pathogens. Although many bacteriocins are now well characterized, much information is still missing or is unavailable to potential users. The assembly of such information in one central resource such as a database would therefore be of great benefit to the exploitation of these bioactive molecules in the present context of increasing antibiotic resistance and natural bio-preservation need. 相似文献2.
BACTIBASE second release: a database and tool platform for bacteriocin characterization 总被引:2,自引:0,他引:2
Riadh Hammami Abdelmajid Zouhir Christophe Le Lay Jeannette Ben Hamida Ismail Fliss 《BMC microbiology》2010,10(1):22
Background
BACTIBASE is an integrated open-access database designed for the characterization of bacterial antimicrobial peptides, commonly known as bacteriocins. 相似文献3.
Vamanu CI Høl PJ Allouni ZE Elsayed S Gjerdet NR 《International journal of nanomedicine》2008,3(1):69-74
Degradation products of titanium implants include free ions, organo-metallic complexes, and particles, ranging from nano to macro sizes. The biological effects, especially of nanoparticles, is yet unknown. The main objective of this study was to develop Ti-protein antigens in physiological solutions that can be used in testing of cellular responses. For this purpose, 0.1% TiO2 nanoparticles less than 100 nm were mixed with human serum albumin (HSA), 0.1% and 1%, in cell culture medium (DMEM, pH 7.2). The Ti concentrations in the resulting solutions were analyzed by inductively coupled plasma mass spectrometry. The stability of the nanoparticles in suspension was analyzed by UV-vis spectrophotometer and Dynamic Light Scattering. The concentration of Ti in suspension was dependent on the presence and concentration of HSA. Albumin prevented high aggregation rate of TiO2 nanoparticles in cell culture medium. It is shown that nano TiO2-protein stable aggregates can be produced under physiological conditions at high concentrations, and are candidates for use in cellular tests. 相似文献
4.
Further development of our recently published Glu(pNA)-containing peptides (Anal. Biochem. 428 (2012) 73–80) provided new fluorogenic substrates for the activated blood coagulation factor XIII. A first series was designed by incorporation of Glu(AMC) at the penultimate position from the N terminus. For the best derivative H-Tyr-Glu(AMC)-Val-Lys-Val-Ile-NH2, a moderate kcat/Km value of 34 s−1 M−1 was determined, which is more than 100-fold reduced compared with the previously reported Glu(pNA) substrates. Furthermore, two fluorescence resonance energy transfer (FRET) substrates were prepared by incorporation of an N-methyl-anthraniloyl fluorophore and a 2,4-dinitrophenyl quencher. Both substrates were excellently cleaved by FXIII-A2∗, which is generated from its zymogen by activation of thrombin in the presence of calcium ions. In the absence and presence of H-Gly-ethyl ester, kcat/Km values of 8010 and 8660 s−1 M−1, respectively, were found for the conversion of H-Lys(N(Me)Abz)-Glu(NH-(CH2)4-NH-Dnp)-Val-Lys-Val-Ile-Gly-NH2 (substrate 8). These values are more than 200-fold improved compared with the Glu(AMC) substrates. Substrate 8 is suitable for the measurement of FXIII-A2∗ activities in plasma samples as well as for in vitro measurements. Furthermore, it was used for the determination of the inhibitory potency of a newly synthesized chloromethyl ketone derivative, Cbz-Phe-Glu(CMK)-Val-Lys-Val-Ile-Gly-NH2, which was found to be a potent irreversible inhibitor of FXIII-A2∗. 相似文献
5.
Jenny Kouretova M. Zouhir Hammamy Anton Epp Kornelia Hardes Stephanie Kallis Linlin Zhang 《Journal of enzyme inhibition and medicinal chemistry》2017,32(1):712-721
West Nile virus (WNV) and Dengue virus (DENV) replication depends on the viral NS2B-NS3 protease and the host enzyme furin, which emerged as potential drug targets. Modification of our previously described WNV protease inhibitors by basic phenylalanine analogs provided compounds with reduced potency against the WNV and DENV protease. In a second series, their decarboxylated P1-trans-(4-guanidino)cyclohexylamide was replaced by an arginyl-amide moiety. Compound 4-(guanidinomethyl)-phenylacetyl-Lys-Lys-Arg-NH2 inhibits the NS2B-NS3 protease of WNV with an inhibition constant of 0.11?µM. Due to the similarity in substrate specificity, we have also tested the potency of our previously described multibasic furin inhibitors. Their further modification provided chimeric inhibitors with additional potency against the WNV and DENV proteases. A strong inhibition of WNV and DENV replication in cell culture was observed for the specific furin inhibitors, which reduced virus titers up to 10,000-fold. These studies reveal that potent inhibitors of furin can block the replication of DENV and WNV. 相似文献
6.
Abdelmajid Zouhir Riadh Hammami Ismail Fliss Jeannette Ben Hamida 《The protein journal》2010,29(6):432-439
Bacteriocins are ribosomally-synthesized peptides or proteins produced by a wide range of bacteria. The antimicrobial activity
of this group of natural substances against foodborne pathogenic and spoilage bacteria has raised considerable interest for
their application in food preservation. Classifying these bacteriocins in well defined classes according to their biochemical
properties is a major step towards characterizing these anti-infective peptides and understanding their mode of action. Actually,
the chosen criteria for bacteriocins’ classification lack consistency and coherence. So, various classification schemes of
bacteriocins resulted various levels of contradiction and sorting inefficiencies leading to bacteriocins belonging to more
than one class at the same time and to a general lack of classification of many bacteriocins. Establishing a coherent and
adequate classification scheme for these bacteriocins is sought after by several researchers in the field. It is not straightforward
to formulate an efficient classification scheme that encompasses all of the existing bacteriocins. In the light of the structural
data, here we revisit the previously proposed contradictory classification and we define new structure-based sequence fingerprints
that support a subdivision of the bacteriocins into 12 groups. The paper lays down a resourceful and consistent classification
approach that resulted in classifying more than 70% of bacteriocins known to date and with potential to identify distinct
classes for the remaining unclassified bacteriocins. Identified groups are characterized by the presence of highly conserved
short amino acid motifs. Furthermore, unclassified bacteriocins are expected to form an identified group when there will be
sufficient sequences. 相似文献
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8.
Yosser Achour Mariem Ben Hamad Souhir Chaabane Ahmed Rebai Sameh Marzouk Nadia Mahfoudh Zouhir Bahloul Leila Keskes Abdellatif Maalej 《Journal of genetics》2017,96(6):911-918
Previous genomewide association studies (GWAS) and meta-analyses have enumerated several genes/loci in major histocompatibility complex region, which are consistently associated with rheumatoid arthritis (RA) in different ethnic populations. Given the genetic heterogeneity of the disease, it is necessary to replicate these susceptibility loci in other populations. In this case, we investigate the analysis of two SNPs, rs13192471 and rs6457617, from the human leukocyte antigen (HLA) region with the risk of RA in Tunisian population. These SNPs were previously identified to have a strong RA association signal in several GWAS studies. A case–control sample composed of 142 RA patients and 123 healthy controls was analysed. Genotyping of rs13192471 and rs6457617 was carried out using real-time PCR methods by TaqMan allelic discrimination assay. A trend of significant association was found in rs6457617 TT genotype with susceptibility to RA (\(P = 0.04\), \(p_{c} = 0.08\), \(\hbox {OR} = 1.73\)). Moreover, using multivariable analysis, the combination of rs6457617*TT–HLA-DRB1*\(04^{+}\) increased risk of RA (\(\hbox {OR} = 2.38\)), which suggest a gene–gene interaction event between rs6457617 located within the HLA-DQB1 and HLA-DRB1. Additionally, haplotypic analysis highlighted a significant association of rs6457617*T–HLA-DRB1*\(04^{+}\) haplotype with susceptibility to RA (\(P = 0.018\), \(p_{c} = 0.036\), \(\hbox {OR} = 1.72\)). An evidence of association was shown subsequently in \(\hbox {antiCCP}^{+}\) subgroup with rs6457617 both in T allele and TT genotype (\(P = 0.01\), \(p_{c} = 0.03\), \(\hbox {OR} = 1.66\) and \(P = 0.008\), \(p_{c} = 0.024\), \(\hbox {OR} = 1.28\), respectively). However, no association was shown for rs13192471 polymorphism with susceptibility and severity to RA. This study suggests the involvement of rs6457617 locus as risk variant for susceptibility/severity to RA in Tunisian population. Secondly, it highlights the gene–gene interaction between HLA-DQB1 and HLA-DRB1. 相似文献
9.
A series of Glu(pNA)-containing peptides was designed to determine the activity of the transglutaminase factor XIIIa at 405 nm due to p-nitroaniline release. The most suitable substrate properties were found for peptides containing the Glu(pNA) residue in the second position from the N terminus. For the best substrate 12 (H-Tyr-Glu(pNA)-Val-Lys-Val-Ile-Gly-NH(2)), a k(cat)/K(m) value of 3531 s(-1)M(-1) was found. Although the k(cat)/K(m) values of the Glu(pNA) peptides are more than 100-fold reduced compared with the previously reported cleavage of natural glutamine-containing substrates such as α(2)-antiplasmin and β-casein, these chromogenic substrates can be useful tools for convenient determination of FXIII-A(2)* activity e.g., for in vitro inhibitor screening. As an example, peptide 12 was used to characterize the inhibition of FXIII-A(2)* by the well-known irreversible inhibitor iodoacetic acid. 相似文献
10.