Search results for "Recombinant protein"
showing 10 items of 707 documents
Seroepidemiology of porcine enteric sapovirus in pig farms in Venezuela
2010
Porcine enteric sapovirus (PES) has been shown to cause diarrhea under experimental conditions in gnotobiotic piglets. However, the role of PES as enteric pathogens in porcine farms remains unclear. To further understand the PES-host interactions under field conditions, a serological survey was carried out. To this end the capsid gene of a PES isolate was cloned in the baculovirus expression system and an ELISA was developed based on virus-like particles from the baculovirus-expressed PES capsid protein. A total of 85 serum samples collected from pigs ranging from 8 weeks to over 54 weeks of age were analyzed. An overall seroprevalence to PESs of 62% was found, with significant differences …
Different Efficiency of Heat Shock Proteins (HSP) to Activate Human Monocytes and Dendritic Cells: Superiority of HSP60
2002
Abstract One essential immunoregulatory function of heat shock protein (HSP) is activation of the innate immune system. We investigated the activation of human monocytes and monocyte-derived dendritic cells (DC) by recombinant human HSP60, human inducible HSP72, and preparations of human gp96 and HSP70 under stringent conditions, in the absence of serum and with highly purified monocytes. HSP60 induced human DC maturation and activated human DC to secrete proinflammatory cytokines. HSP72 induced DC maturation to a lesser extent, but activated human monocytes and immature DC as efficiently as HSP60 to release proinflammatory cytokines. The independence of the effects of HSP60 and HSP72 from …
Characterization of a T cell-derived lymphokine that acts synergistically with IL 3 on the growth of murine mast cells and is identical with IL4
1987
Abstract A mast cell-like cell line (SN-1) was established with the aid of growth factor(s) present in the supernatant of a Con A-stimulated L3T4 + T cell line. In analogy to other mast cell lines, IL 3 was identified as a growth factor for SN-1 cells. In addition, a second lymphokine produced by the T cells synergistically enhanced the IL 3-induced growth. This factor, originally termed mast cell growth enhancing factor (MaGEF), could be separated from IL 2, IL 3, a CSF-like activity and was purified to homogeneity. The N-terminal amino acid sequence (8 residues) and the functional properties of this lymphokine proved to be identical with those reported for BSF-1 (IL 4). Unless applied at …
Recombinant expression, in vitro refolding, and biophysical characterization of the N-terminal domain of T1R3 taste receptor
2012
Facteur d'impact (5 ans) : 1,617Notoriété à 2 ans : Acceptable (biochem.res.methods); The sweet taste receptor is a heterodimeric receptor composed of the T1R2 and T1R3 subunits, while T1R1 and T1R3 assemble to form the umami taste receptor. T1R receptors belong to the family of class C G-protein coupled receptors (GPCRs). In addition to a transmembrane heptahelical domain, class C GPCRs have a large extracellular N-terminal domain (NTD), which is the primary ligand-binding site. The T1R2 and T1R1 subunits have been shown to be responsible for ligand binding, via their NTDs. However, little is known about the contribution of T1R3-NTD to receptor functions. To enable biophysical characteriza…
Regulation of Human Mitochondrial Aldehyde Dehydrogenase (ALDH-2) Activity by Electrophiles in Vitro
2011
Recently, mitochondrial aldehyde dehydrogenase (ALDH-2) was reported to reduce ischemic damage in an experimental myocardial infarction model. ALDH-2 activity is redox-sensitive. Therefore, we here compared effects of various electrophiles (organic nitrates, reactive fatty acid metabolites, or oxidants) on the activity of ALDH-2 with special emphasis on organic nitrate-induced inactivation of the enzyme, the biochemical correlate of nitrate tolerance. Recombinant human ALDH-2 was overexpressed in Escherichia coli; activity was determined with an HPLC-based assay, and reactive oxygen and nitrogen species formation was determined by chemiluminescence, fluorescence, protein tyrosine nitration,…
Glucosylation of Rho proteins by Clostridium difficile toxin B.
1995
TOXIN A and B, the major virulence factors of Clostridium difficile, are the causative agents of antibiotic-associated pseudomembran-ous colitis. In cultured cell lines their potent cytotoxicity results from their ability to induce disaggregation of the microfilament cytoskeleton1,2. Toxin B acts on the low-molecular-mass GTPase Rho A3,4, which is involved in the regulation of the actin cytoskeleton. We report here that toxin B catalyses the incorporation of up to one mole of glucose per mole of RhoA at the amino acid thre-onine at position 37. The modification was identified and localized by tandem electrospray mass spectrometry. UDP-glucose selectively serves as cosubstrate for the monogl…
Bradykinin-induced Internalization of the Human B2Receptor Requires Phosphorylation of Three Serine and Two Threonine Residues at Its Carboxyl Tail
1999
The binding of bradykinin (BK) to B2 receptor triggers the internalization of the agonist-receptor complex. To investigate the mechanisms and the receptor structures involved in this fundamental process of receptor regulation, the human B2 receptor was mutated within its cytoplasmic tail by complementary strategies of truncation, deletion, and amino acid substitution. Ligand binding, signal transduction, internalization as well as phosphorylation were studied for the mutated receptors expressed in COS, CHO, and HEK 293 cells. Truncation of 44 out of 55 amino acid residues of the receptor's cytoplasmic tail corresponding to positions 321-364 did not alter the kinetics of BK binding and the r…
A critical evaluation of caplacizumab for the treatment of acquired thrombotic thrombocytopenic purpura
2020
Introduction: Acquired thrombotic thrombocytopenic purpura (aTTP) is a thrombotic microangiopathy caused by inhibitory autoantibodies against ADAMTS13 protein. Until recently, the combination of plasma exchange (PEX) and immunosuppression has been the standard front-line treatment in this disorder. However, aTTP-related mortality, refractoriness, and relapse are still a matter of concern. Areas covered: The better understanding of the pathophysiological mechanisms of aTTP has allowed substantial improvements in the diagnosis and treatment of this disease. Recently, the novel anti-VWF nanobody caplacizumab has been approved for acute episodes of aTTP. Caplacizumab is capable to block the adh…
Fluorescence Properties of the Chromophore-Binding Domain of Bacteriophytochrome from Deinococcus radiodurans
2013
Fluorescent proteins are versatile tools for molecular imaging. In this study, we report a detailed analysis of the absorption and fluorescence properties of the chromophore-binding domain from Deinococcus radiodurans and its D207H mutant. Using single photon counting and transient absorption techniques, the average excited state lifetime of both studied systems was about 370 ps. The D207H mutation slightly changed the excited state decay profile but did not have a considerable effect on the average decay time of the system or the shape of the absorption and emission spectra of the biliverdin chromophore. We confirmed that the fluorescence properties of both samples are very similar in vivo…
REDUCTION OF NILUTAMIDE BY NO SYNTHASES : IMPLICATIONS FOR THE ADVERSE EFFECTS OF THIS NITROAROMATIC ANTIANDROGEN DRUG
2003
Nitric oxide synthases (NOSs) are flavohemeproteins that catalyze the oxidation of l-arginine to l-citrulline with formation of the widespread signal molecule NO. Beside their fundamental role in NO biosynthesis, these enzymes are also involved in the formation of reactive oxygen species and in the interactions with some xenobiotic compounds. Nilutamide is a nonsteroidal antiandrogen that behaves as a competitive antagonist of the androgen receptors and is proposed in the treatment of metastatic prostatic carcinoma. However, therapeutic effects of nilutamide are overshadowed by the occurrence of several adverse reactions mediated by toxic mechanism(s), which remain(s) poorly investigated. H…