Search results for "immunoglobulin"
showing 10 items of 841 documents
Multiple IgE recognition on the major allergen of the Parietaria pollen Par j 2
2015
The interaction between IgE antibodies and allergens is a key event in triggering an allergic reaction. The characterization of this region provides information of paramount importance for diagnosis and therapy. Par j 2 Lipid Transfer Protein is one of the most important allergens in southern Europe and a well-established marker of sensitization in Parietaria pollen allergy. The main aim of this study was to map the IgE binding regions of this allergen and to study the pattern of reactivity of individual Parietaria-allergic patients. By means of gene fragmentation, six overlapping peptides were expressed in Escherichia coli, and their IgE binding activity was evaluated by immunoblotting in …
Antibody inhibition of the transcriptase activity of the rotavirus DLP: a structural view.
2001
On entering the host cell the rotavirus virion loses its outer shell to become a double-layered particle (DLP). The DLP then transcribes the 11 segments of its dsRNA genome using its own transcriptase complex, and the mature mRNA emerges along the 5-fold axis. In order to better understand the transcription mechanism and the role of VP6 in transcription we have studied three monoclonal antibodies against VP6: RV-238 which inhibits the transcriptase activity of the DLP; and RV-133 and RV-138 which have no effect on transcription. The structures obtained by cryo-electron microscopy of the DLP/Fab complexes and by X-ray crystallography of the VP6 trimer and the VP6/Fab-238 complex have been co…
Modeling of the role of conformational dynamics in kinetics of the antigen-antibody interaction in heterogeneous phase.
2012
[EN] A novel approach that may potentially be used to study biomolecular interactions including the simultaneous determination of structural and kinetic binding parameters is described in this Article for the first time. It allows a rigid distinction between the possible reaction mechanisms of biomolecular recognition, induced fit and conformational selection. The relative importance of the two pathways is determined not by comparing rate constants but the structural aspects of the interaction instead. So the exact location of antigen molecules with respect to the capture antibody is depicted experimentally, avoiding the use of X-ray crystallography. The proposed pattern is applied to study…
Monoclonal antibody to a DNA-binding domain of p53 mimics charge structure of DNA: anti-idiotypes to the anti-p53 antibody are anti-DNA
2004
Antibodies to DNA are important markers of various autoimmune diseases and can be pathogenic; however, their generation is not understood. We previously reported that anti-DNA antibodies could be induced in mice by idiotypic immunization to PAb-421, an antibody to a DNA-binding domain of p53. We now report that two monoclonal antibodies of moderate affinity (K(D) asymptotically equal to 10(-7)), raised from PAb-421-immunized mice, specifically recognized both PAb-421 and DNA. These antibodies feature multiple arginine residues in the antigen-binding site, a unique characteristic of disease-associated anti-DNA antibodies; nevertheless, these anti-DNA antibodies show specific complementarity …
Receptor protein-tyrosine phosphatases: origin of domains (catalytic domain, Ig-related domain, fibronectin type III module) based on the sequence of…
2001
Abstract Reversible tyrosine phosphorylation of proteins is one of the major regulatory physiological events in response to cell-cell- and cell-matrix contact in Metazoa. Previously it was documented that the tyrosine phosphorylating enzymes, the tyrosine kinases (TKs), are autapomorphic characters of Metazoa, including sponges. In this paper the tyrosine dephosphorylating enzymes, the protein-tyrosine phosphatases (PTPs), are studied which can be grouped into two subfamilies, the soluble PTPs and the receptor PTPs (RPTPs). PTPs are characterized by one PTPase domain which interestingly comprises sequence similarity to yeast PTPs. In contrast to the PTPs, the RPTPs – which have been found o…
Multiple Ig-like featuring genes divergent within and among individuals of the marine sponge Geodia cydonium.
1998
Abstract The receptor tyrosine kinase of the marine sponge Geodia cydonium features two extracellular Ig-like domains in which we recently documented RT-PCR polymorphism among individuals. Genomic-PCR analysis presented here revealed 14 unique sequences from four sponges, differing predominantly in the sequence of an intron which splits the Ig-like domains. Nevertheless, analysis of putative coding regions in 19 distinct clones (156–159 aa) from seven sponges revealed 69 positions of nucleotide substitutions, 67.6% of them non-synonymous, translating into 43 positions of divergent residues. Excluding aa deletions, these 19 sequences share pairwise aa identities of 89–99%. In three sponges, …
Molecular spreading and predictive value of preclinical IgE response to Phleum pratense in children with hay fever.
2012
Background IgE sensitization against grass pollen is a cause of seasonal allergic rhinitis. Objective We sought to investigate the evolution at the molecular level and the preclinical predictive value of IgE responses against grass pollen. Methods The German Multicentre Allergy Study examined a birth cohort born in 1990. A questionnaire was administered yearly, and blood samples were collected at 1, 2, 3, 5, 6, 7, 10, and 13 years of age. Grass pollen–related seasonal allergic rhinitis (SARg) was diagnosed according to nasal symptoms in June/July. Serum IgE antibodies to Phleum pratense extract and 8 P pratense molecules were tested with immune-enzymatic singleplex and multiplex assays, res…
Expansion of intracellular IFN-γ positive lymphocytes during Mycoplasma agalactiae infection in sheep.
2010
Abstract A method to assess the expansion of antigen-specific intracellular IFN-γ positive T cell subsets during the infection will be helpful for a better understanding of mycoplasmal infections physiopathology in the sheep. We analysed the percentage of antigen-specific lymphocytes positive for intracellular IFN-γ during the infection of sheep with Mycoplasma agalactiae by culturing peripheral blood mononuclear cells of infected or uninfected animals with irradiated M. agalactiae . The expansion of antigen-specific IFN-γ positive lymphocytes in infected sheep was initially sustained by CD4 + T cells at day 15 after infection, when antigen specific IgG start to be detectable, followed by C…
LA CHLAMYDIA PNEUMONIAE È CORRELABILE CON LA ROTTURA DELLA PLACCA ATEROSCLEROTICA? RUPTURE OF THE ATHEROSCLEROTIC PLAQUE: IS CHLAMYDIA PNEUMONIAE A P…
2006
Background. The natural history of atherosclerosis has not clearly been elucidated yet. Some works reported that flogosis plays a role in plaque instability. Why does this inflammatory process start? We investigated the correlation between Chlamydia pneumoniae acute infection and plaque rupture. Methods. We compared blood concentrations of IgM anti-Chlamydia pneumoniae in patients affected by acute myocardial infarction (AMI) and in patients affected by stable angina. Results. Our results showed a minimal statistical difference, with a more positive value in patients with AMI. Subsequently, the group affected by AMI was divided into two subgroups with and without plaque rupture: the subgrou…
The role of serum free light chain as biomarker of Myasthenia Gravis
2022
Background and aim: Myasthenia gravis (MG) is a B lymphocyte–mediated disease affecting neuromuscular transmission. The clinical course of MG is unpredictable due to the fluctuating nature and heterogeneity of the disease. Increased levels of free light chains (FLC), which reflect B cell activation, have been detected in different autoimmune disorders. In this study, we evaluated the potential role of FLC as diagnostic and prognostic biomarkers of MG. Materials and methods: 74 MG patients and 52 healthy individuals were included in the study. Serum FLC levels were measured by turbidimetric assay (Freelite, The Binding Site Group Ltd) on the Optilite Analyser System in both groups. In MG pat…