Search results for "chicken"
showing 10 items of 190 documents
VanB-VanC1 Enterococcus gallinarum, Italy
2005
To the Editor: We report detecting a vanB determinant in Enterococcus gallinarum in poultry in Italy. High-level vanA-mediated glycopeptide resistance has been described for E. gallinarum and E. casseliflavus (1–4), and vanB-mediated vancomycin resistance has been frequently described for E. faecalis and E. faecium. However, vanB-mediated resistance in isolates of E. gallinarum has been described only in sporadic nosocomial cases of infection or colonization (5,6). In January 2005, a study of contamination by foodborne organisms in slaughtered broiler carcasses was conducted in Sicily. To detect glycopeptide-resistant enterococci (GRE), each carcass was placed in a bag with 100 mL sterile b…
Immunogenicity and safety of two doses of tetravalent measles-mumps-rubella-varicella vaccine in healthy children.
2006
Combination vaccines against common childhood diseases are widely used, provide an improved coverage, are more convenient and are more cost-effective than multiple injections. We conducted a study to evaluate the safety and immunogenicity of a combined measles-mumps-rubella-varicella (MMRV) candidate vaccine in comparison with the separate administration of licensed measles-mumps-rubella (MMR; Priorix) and varicella (V; Varilrix) vaccines.Healthy children 12-18 months of age received 2 doses of MMRV vaccine (3 lots) 6-8 weeks apart (MMRV group) or 1 dose of MMR vaccine administered concomitantly with 1 dose of varicella vaccine, followed by a second dose of MMR at 6-8 weeks later (MMR+V gro…
Design and construction of highly stable, protease-resistant chimeric avidins.
2005
The chicken avidin gene family consists of avidin and seven separate avidin-related genes (AVRs) 1-7. Avidin protein is a widely used biochemical tool, whereas the other family members have only recently been produced as recombinant proteins and characterized. In our previous study, AVR4 was found to be the most stable biotin binding protein thus far characterized (T(m) = 106.4 degrees C). In this study, we studied further the biotin-binding properties of AVR4. A decrease in the energy barrier between the biotin-bound and unbound state of AVR4 was observed when compared with that of avidin. The high resolution structure of AVR4 facilitated comparison of the structural details of avidin and …
Construction of a dual chain pseudotetrameric chicken avidin by combining two circularly permuted avidins.
2004
Two distinct circularly permuted forms of chicken avidin were designed with the aim of constructing a fusion avidin containing two biotin-binding sites in one polypeptide. The old N and C termini of wild-type avidin were connected to each other via a glycine/serine-rich linker, and the new termini were introduced into two different loops. This enabled the creation of the desired fusion construct using a short linker peptide between the two different circularly permuted subunits. The circularly permuted avidins (circularly permuted avidin 5 → 4 and circularly permuted avidin 6 → 5) and their fusion, pseudotetrameric dual chain avidin, were biologically active, i.e. showed biotin binding, and…
Tetravalent single-chain avidin: from subunits to protein domains via circularly permuted avidins
2005
scAvd (single-chain avidin, where two dcAvd are joined in a single polypeptide chain), having four biotin-binding domains, was constructed by fusion of topologically modified avidin units. scAvd showed similar biotin binding and thermal stability properties as chicken avidin. The DNA construct encoding scAvd contains four circularly permuted avidin domains, plus short linkers connecting the four domains into a single polypeptide chain. In contrast with wild-type avidin, which contains four identical avidin monomers, scAvd enables each one of the four avidin domains to be independently modified by protein engineering. Therefore the scAvd scaffold can be used to construct spatially and stoich…
Conformational Changes in the Nucleosome Followed by the Selective Accessibility of Histone Glutamines in the Transglutaminase Reaction: Effects of …
2001
Transglutaminases, the enzymes that catalyze the acyl-transfer reaction between glutamine and primary amines, have been used to introduce probes into proteins in order to perform structural studies using physical techniques. Here we use an original approach in which the increasing accessibility of the glutamines of core histones to TGase is used to monitor the salt-induced conformational changes of the nucleosome. The rationale of this strategy is that the accessibility of a glutamine to transglutaminase depends on the blockage due to the presence of either other histones or DNA. At low ionic strength, only glutamines on the N-terminal tails of H2B and H3 are labeled with monodansylcadaveri…
Binding Properties of HABA-Type Azo Derivatives to Avidin and Avidin-Related Protein 4
2006
Summary The chicken genome encodes several biotin-binding proteins, including avidin and avidin-related protein 4 (AVR4). In addition to D -biotin, avidin binds an azo dye compound, 4-hydroxyazobenzene-2-carboxylic acid (HABA), but the HABA-binding properties of AVR4 are not yet known. Differential scanning calorimetry, UV/visible spectroscopy, and molecular modeling were used to analyze the binding of 15 azo molecules to avidin and AVR4. Significant differences are seen in azo compound preferences for the two proteins, emphasizing the importance of the loop between strands β3 and β4 for azo ligand recognition; information on these loops is provided by the high-resolution (1.5 A) X-ray stru…
Controlling quaternary structure assembly: subunit interface engineering and crystal structure of dual chain avidin.
2006
Dual chain avidin (dcAvd) is an engineered avidin form, in which two circularly permuted chicken avidin monomers are fused into one polypeptide chain. DcAvd can theoretically form two different pseudotetrameric quaternary assemblies because of symmetry at the monomer-monomer interfaces. Here, our aim was to control the assembly of the quaternary structure of dcAvd. We introduced the mutation I117C into one of the circularly permuted domains of dcAvd and scanned residues along the 1-3 subunit interface of the other domain. Interestingly, V115H resulted in a single, disulfide locked quaternary assembly of dcAvd, whereas I117H could not guide the oligomerisation process even though it stabilis…
Chicken Avidin-related Protein 4/5 Shows Superior Thermal Stability when Compared with Avidin while Retaining High Affinity to Biotin
2003
The protein chicken avidin is a commonly used tool in various applications. The avidin gene belongs to a gene family that also includes seven other members known as the avidin-related genes (AVR). We report here on the extremely high thermal stability and functional characteristics of avidin-related protein AVR4/5, a member of the avidin protein family. The thermal stability characteristics of AVR4/5 were examined using a differential scanning calorimeter, microparticle analysis, and a microplate assay. Its biotin-binding properties were studied using an isothermal calorimeter and IAsys optical biosensor. According to these analyses, in the absence of biotin AVR4/5 is clearly more stable (T…
Experimental and theoretical NMR studies of interaction between phenylalanine derivative and egg yolk lecithin
2014
The interaction of phenylalanine diamide (Ac-Phe-NHMe) with egg yolk lecithin (EYL) in chloroform was studied by 1H and 13C NMR. Six complexes EYL–Ac-Phe-NHMe, stabilized by N–H···O or/and C–H···O hydrogen bonds, were optimized at M06-2X/6-31G(d,p) level. The assignment of EYL and Ac-Phe-NHMe NMR signals was supported using GIAO (gauge including atomic orbital) NMR calculations at VSXC and B3LYP level of theory combined with STO-3Gmag basis set. Results of our study indicate that the interaction of peptides with lecithin occurs mainly in the polar ‘head’ of the lecithin. Additionally, the most probable lecithin site of H-bond interaction with Ac-Phe-NHMe is the negatively charged oxygen in …