Molecules and cells

The signaling properties of the gasotransmitter molecule hydrogen sulfide (H2S), which is endogenously generated in plant cells, are mainly observed during persulfidation, a protein post-translational modification (PTM) that affects redox-sensitive cysteine residues. There is growing experimental evidence that H2S in higher plants may function as a mechanism of response to environmental stress conditions.

7p partimesinhvien 08-05-2020 31 0   Download

In a previous study, we used the genome of serogroup B Meningococcus to identify novel vaccine candidates. One of these molecules, GNA33, is well conserved among Meningococcus B strains, other Meningococcus serogroups and Gonococcus and induces bactericidal antibodies as a result of being a mimetic antigen of the PorA epitope P1.2. GNA33 encodes a 48-kDa lipoprotein that is 34.5% identical with membrane-bound lytic transglycosylase A (MltA) from Escherichia coli. In this study, we expressed GNA33, i.e....

10p system191 01-06-2013 36 4   Download

Affinity reagents capable of selective recognition of the different human immunoglobulin isotypes are important detection and purification tools in biotechnology. Here we describe the development and characterization of affinity proteins (affibodies) showing selective binding to human IgA. From protein libraries constructed by combinatorial mutagenesis of a 58-amino-acid, three-helix bundle domain derived from the IgG-binding staphylococcal protein A, variants showing IgA binding were selected by using phage display technology and IgA monoclonal antibodies (myeloma) as target molecules. ...

9p system191 01-06-2013 39 3   Download

Department of Chemistry ‘IFM’, University of Torino, Italy; 2Department of Biology, University ‘Roma Tre’, Rome, Italy; 3Department of Structural and Functional Biology, University of Insubria, Italy Haem binding to human serum albumin (HSA) endows the protein with peculiar spectroscopic properties. Here, the effect of ibuprofen and warfarin on the spectroscopic properties of ferric haem –human serum albumin (ferric HSA–haem) and of ferrous nitrosylated haem –human serum albumin (ferrous HSA –haem-NO) is reported.

7p system191 01-06-2013 46 3   Download

The siglecs (sialic acid-binding Ig-like lectins) are a distinct subset of the Ig superfamily with adhesion-molecule-like structure. We describe here a novel member of the siglec protein family that shares a similar structure including five Ig-like domains, a transmembrane domain, and a cytoplasmic tail containing two ITIM-signaling motifs. Siglec10 was identified through database mining of an asthmatic eosinophil EST library. Using the Stanford G3 radiation hybrid panel we were able to localize the genomic sequence of siglec-10 within the cluster of genes on chromosome 19q13.

14p system191 01-06-2013 43 6   Download

The involvement of the lysine residue present at the active site of Ehrlich ascites carcinoma (EAC) cell glyceraldehyde-3-phosphate dehydrogenase (Gra3P DH) was investigated by using the lysine specific reagents trinitrobenzenesulfonic acid (TNBS) and pyridoxal phosphate (PP). Both TNBS and PP inactivated EAC cell Gra3P DH with pseudo-first-order kinetics with the rate dependent on modifier concentration. Kinetic analysis, including a Tsou plot, indicated that both TNBS and PP apparently react with one lysine residue per enzyme molecule.

8p system191 01-06-2013 37 3   Download

Nitrogen monoxide (NO) is a cytotoxic effector molecule produced by macrophages that results in Fe mobilization from tumour target cells which inhibits DNA synthesis and mitochondrial respiration. It is well known that NO has a high affinity for Fe, and we showed that NO-mediated Fe mobilization is markedly potentiated by glutathione (GSH) generated by the hexose monophosphate shunt [Watts, R.N. & Richardson, D.R. (2001) J. Biol. Chem. 276, 4724–4732]. We hypothesized that GSH completes the coordination shell of an NO–Fe complex that is released from the cell.

10p research12 01-06-2013 47 3   Download

The structure of the lipopolysaccharide (LPS) of Pseudomonas aeruginosa immunotype 1 was studied after mild acid and strong alkaline degradations by MS and NMR spectroscopy. Three types of LPS molecules were found, including those with an unsubstituted glycoform 1 core (A) or an isomeric glycoform 2 core substituted with one O-polysaccharide repeating unit (B) or with a long-chain O-polysaccharide. Therefore, of two core glycoforms, only glycoform 2 accepts the O-polysaccharide. LPS molecules, an O-acetyl group is present in the outer core region at unknown position....

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Conventional and saturation transfer electron paramagnetic resonance spectroscopy (EPR and ST EPR) was used to study the orientation of probe molecules in muscle fibers in different intermediate states of the ATP hydrolysis cycle. A separate procedure was used to obtain ST EPR spectra with precise phase settings even in the case of samples with low spectral intensity. Fibers prepared from rabbit psoas muscle were labeled with isothiocyanate spin labels at the reactive thiol sites of the catalytic domain of myosin....

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Subunits (a, b and c) of the interleukin-2 receptor complex (IL-2R) are involved in both proliferative and activationinduced cell death (AICD) signaling of T cells. In addition, the signaling b and c chains are shared by other cytokines (e.g. IL-7, IL-9, IL-15). However, the molecular mechanisms responsible for recruiting/sorting the a chains to the signaling chains at the cell surface are not clear.

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Lipid rafts are liquid-ordered membrane microdomains with a unique protein and lipid composition found on the plasma membrane of most, if not all, mammalian cells. A large number of signalling molecules are concentrated within rafts, which have been proposed to function as signalling centres capable of facilitating efficient and specific signal transduction. This review summarizes current knowledge regarding the composition, structure, and dynamic nature of lipid rafts, as well as a number of different signalling path- ways that are compartmentalized within these microdomains....

16p research12 01-06-2013 37 3   Download

To gain insight in the subcellular localization of tumor necrosis factor receptor-associated factor (TRAF4) we analyzed GFP chimeras of full-length TRAF4 and various deletionmutants derived thereof.While TRAF4–GFP (T4– GFP) was clearlylocalized in the cytoplasm, the N-terminal deletion mutant, T4(259–470), comprising the TRAF domain of the molecule, and a C-terminal deletion mutant consisting mainlyof the RING and zinc finger domains of TRAF4 were both localized predominantlyto the nucleus....

11p research12 29-04-2013 49 4   Download

Human interleukin-11 (hIL-11) is a pleiotropic cytokine that is involved in numerous biological activities such as hematopoiesis, osteoclastogenesis, neurogenesis and female fertility. IL-11 is obviously a key reagent to study the IL-11 receptors. However, conventional radio-iodination techni-ques lead to a loss of IL-11 bioactivity. Here, we report the construction and the production of a new recombinant human IL-11 (FPDIL-11). In this molecule, a speci®c phosphorylation site (RRASVA) has been introduced at the N-terminus of rhIL-11. ...

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In human neutrophils, both changes in intracellular Ca 2+ concentrations, [Ca 2+ ] i , and activation of phosphatidyl-inositol-3 kinase (PtdIns3K) have been proposed to play a role in regulating cellular function induced by chemoattr-actants. In this studywe have investigated the role of [Ca 2+ ] i and its effector molecule calmodulin in human neutrophils.

10p research12 23-04-2013 43 2   Download

ThenblAfamily of genes encodes for small proteins neces-sary for the ordered degradation of phycobilisomes under certain stress conditions, a process known as chlorosis. Genes homologous tonblAseem to occur in all phycobili-some-containingorganisms.However, todate, nomolecular mechanism is known for the action of NblA, nor have the gene products been characterized to understand the physical properties of the molecule and thus help elucidate the mechanism on a structural basis.

8p research12 23-04-2013 45 4   Download

The ability of aminoacyl-tRNA synthetases to distinguish betweensimilaraminoacidsiscrucial foraccuratetrans-lation of the genetic code. Saccharomyces cerevisiae seryl-tRNA synthetase (SerRS) employs tRNA-dependent recognition of its cognate amino acid serine [Lenhard, B., Filipic, S., Landeka, I., Skrtic, I., So¨ll, D. & Weygand-Durasevic, I. (1997)J. Biol. Chem.272, 1136–1141]. Herewe show that dimeric SerRS enzyme complexed with one molecule of tRNA Ser is more specific and more efficient in catalyzing seryl-adenylate formation than the apoenzyme alone. ...

9p tumor12 22-04-2013 38 2   Download

Opacity-associated (Opa) proteins are outer membrane proteins which play a critical role in the adhesion of patho-genicNeisseriaspp. to epithelial and endothelial cells and polymorphonuclear neutrophils. The adherence is mainly mediated by the CD66-epitope-containing members of the carcinoembryonic-antigen family of human cell-adhesion molecules (CEACAM). For the analysis of the specific in-teractions of individual Opa proteins with their receptors, pure protein is needed in its native conformation. ...

9p tumor12 22-04-2013 34 2   Download

Thea-phycoerythrocyanin subunits of the different phy-coerythrocyanin complexes of the phycobilisomes from the cyanobacterium Mastigocladus laminosusperform a remarkable photochemistry. Similar to phytochromes – the photoreceptors of higher plants – the spectral pro-perties of the molecule reversibly change according to the irradiation wavelength. To enable extensive analyses,the protein has been produced at high yield by improving purification protocols.

10p tumor12 22-04-2013 46 3   Download

Protein molecular modelling and ligand docking were employed for the design of anthraquinone galactosyl-bio-mimetic dye ligands (galactosyl-mimodyes) for the target enzyme galactose dehydrogenase (GaDH). Using appro-priate modelling methodology, a GaDH model was build based on a glucose-fructose oxidoreductase (GFO) protein template.

15p tumor12 22-04-2013 46 2   Download

This review summarizes the most recent state of haemo-globin (Hb) research based on the literature and our own results. In particular, an attempt is made to form a unified picture for haemoglobin function by reconciling the cooperative oxygen binding with the stabilization of the bound dioxygen in aqueous solvent. The HbA molecule contains two types ofabcontacts. One type is thea1b2or a2b1 contacts, called sliding contacts, and these are strongly associated with the cooperative binding of O2to the a2b2 tetramer. ...

11p tumor12 20-04-2013 36 2   Download