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Antigen Interactions (antigen + interaction)

Distribution by Scientific Domains

Chemistry	44%
Medical Sciences	22%

Selected Abstracts

Use of nitrocellulose films for affinity-directed mass spectrometry for the analysis of antibody/antigen interactions

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 18 2001
Shuqing Sun
Combination of affinity extraction procedures with mass spectrometric analyses is termed affinity-directed mass spectrometry, a technique that has gained broad interest in immunology and is extended here with several improvements from methods used in previous studies. A monoclonal antibody was immobilized on a nitrocellulose (NC) membrane, allowing the corresponding antigen to be selectively captured from a complex solution for analysis by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). This method was also used to rapidly determine the approximate binding region responsible for the antibody/antigen interaction. The tryptic fragments of antigen protein in buffer were applied to the antibody immobilized on NC film and allowed to interact. The NC film was then washed to remove salts and other unbound components, and subjected to analysis by MALDI-TOFMS. Using interferon-,2a and anti-interferon-,2a monoclonal antibody IgG as a model system, we successfully extracted the antigen protein and determined the approximate binding region for the antigen/antibody interaction (i.e., the tryptic fragment responsible). Copyright © 2001 John Wiley & Sons, Ltd. [source]

Microscale characterization of the binding specificity and affinity of a monoclonal antisulfotyrosyl IgG antibody

ELECTROPHORESIS, Issue 12 2008
Klaus S. Lassen Dr.
Abstract Sulfation is a potentially important post-translational modification of proteins and has been demonstrated in a number of polypeptides, notably in gastrointestinal hormones. In contrast to phosphorylation, however, the investigation of sulfation patterns in tissues and on purified proteins has been complicated by the absence of specific immunoreagents (antibodies) for this modification as well as the chemical lability of the sulfate group. Here, we investigate the properties of a novel mAb against sulfated tyrosyl groups (anti-Tyr(SO3H) antibody) using CE and a panel of sulfated and nonsulfated peptides and proteins. The data show that the anti-Tyr(SO3H) antibody is completely specific for compounds containing sulfated tyrosyls. Affinity electrophoresis experiments allowed us to estimate dissociation constants for sulfated hirudin fragment (56,65), gastrin-17, and cholecystokinin octapeptide (CCK8) in the 1,3,,M range. The affinity of the antibody toward complement 4 protein that contains three sulfotyrosines was analyzed by surface plasmon resonance technology and modeled according to a bivalent-binding model which yielded a Kd1 of 20.1,,M for the monovalent complex. The same binding was studied by CE and found to be in the micromolar scale albeit with some uncertainty due to complex separation patterns. The work illustrates the amount of information on antibody,antigen interactions that may be obtained with microelectrophoretic methods consuming minute quantities of material. Furthermore the specificity of this antibody could be confirmed in one operation using an array of sulfated and nonsulfated compounds. [source]

A label-free protein microfluidic array for parallel immunoassays

ELECTROPHORESIS, Issue 20 2006
Zhan-Hui Wang
Abstract A label-free protein microfluidic array for immunoassays based on the combination of imaging ellipsometry and an integrated microfluidic system is presented. Proteins can be patterned homogeneously on substrate in array format by the microfluidic system simultaneously. After preparation, the protein array can be packed in the microfluidic system which is full of buffer so that proteins are not exposed to denaturing conditions. With simple microfluidic channel junction, the protein microfluidic array can be used in serial or parallel format to analyze single or multiple samples simultaneously. Imaging ellipsometry is used for the protein array reading with a label-free format. The biological and medical applications of the label-free protein microfluidic array are demonstrated by screening for antibody,antigen interactions, measuring the concentration of the protein solution and detecting five markers of hepatitis,B. [source]

Identification of antigenic targets of paraproteins by expression cloning does not support a causal role of chronic antigenic stimulation in the pathogenesis of multiple myeloma and MGUS

INTERNATIONAL JOURNAL OF CANCER, Issue 2 2007
Klaus-Dieter Preuss
Abstract Antigenic targets of monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM) paraproteins have been suggested to play an important role as growth stimulators in the pathogenesis of these neoplasms. To identify such targets, we screened cDNA libraries from human testis, lung and breast cancer, bovine and porcine muscle and wheat germ for reactivity with paraproteins in the sera from 115 patients with MGUS and MM. Of >6 × 108 paraprotein,antigen interactions screened, an IgA paraprotein from a female patient bound to sperm-specific cylicin-2, and 3 IgG paraproteins bound to tripeptidyl-peptidase-II (TPP-2), insulin-like growth-factor binding-protein-2 (IGFBP-2) and porcine kinesin. Specificity was confirmed by reverse Western blots using recombinant antigens. The broad spectrum of auto-, allo- and heteroantigens as targets of human paraproteins in patients without signs of chronic antigenic stimulation renders a causal role of the antigenic stimulus in the pathogenesis of MGUS and MM unlikely. © 2007 Wiley-Liss, Inc. [source]

Involvement of HAb18G/CD147 in T cell activation and immunological synapse formation

JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 8 2010
Jinsong Hu
Abstract HAb18G/CD147, a glycoprotein of the immunoglobulin super-family (IgSF), is a T cell activation-associated molecule. In this report, we demonstrated that HAb18G/CD147 expression on both activated CD4+ and CD8+ T cells was up-regulated. In vitro cross-linking of T cells with an anti-HAb18G/CD147 monoclonal antibody (mAb) 5A12 inhibited T cells proliferation upon T cell receptor stimulation. Such co-stimulation inhibited T cell proliferation by down-regulating the expression of CD25 and interleukin-2 (IL-2), decreased production of IL-4 but not interferon-,. Laser confocal imaging analysis indicated that HAb18G/CD147 was recruited to the immunological synapse (IS) during T cell activation; triggering HAb18G/CD147 on activated T cells by anti-HAb18G/CD147 mAb 5A12 strongly dispersed the formation of the IS. Further functional studies showed that the ligation of HAb18G/CD147 with mAb 5A12 decreased the tyrosine phosphorylation and intracellular calcium mobilization levels of T cells. Through docking antibody,antigen interactions, we demonstrated that the function of mAb 5A12 is tightly dependent on its specificity of binding to N-terminal domain I, which plays pivotal role in the oligomerization of HAb18G/CD147. Taken together, we provide evidence that HAb18G/CD147 could act as a co-stimulatory receptor to negatively regulate T cell activation and is functionally linked to the formation of the IS. [source]

Studies on fluorescence resonance energy transfer between dyes and water-soluble quantum dots

LUMINESCENCE: THE JOURNAL OF BIOLOGICAL AND CHEMICAL LUMINESCENCE, Issue 4-5 2005
Qidan Chen
Abstract In this work, donor,acceptor complexes were formed based on antibody,antigen interactions. Immunoglobulin antigen (mouse-IgG) was effectively conjugated to mercaptopropyl acid-modified CdTe quantum dot synthesized in aqueous solution via electrostatic interaction, while organic dyes,tetramethylrhodamine isothiocyanate (TRITC) were attached to the corresponding antibody (anti-mouse IgG). The mutual affinity of the antigen and antibody brought the CdTe quantum dot and TRITC sufficiently close together to allow the resonance dipole,dipole coupling required for fluorescence resonance energy transfer to occur. The formation of immunocomplexes resulted in fluorescence resonance energy transfer from the CdTe quantum dot donors to the TRITC acceptors. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Surface plasmon resonance label-free monitoring of antibody antigen interactions in real time

BIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION, Issue 1 2007
Asta Kausaite
Abstract Detection of biologically active compounds is one of the most important topics in molecular biology and biochemistry. One of the most promising detection methods is based on the application of surface plasmon resonance for label-free detection of biologically active compounds. This method allows one to monitor binding events in real time without labeling. The system can therefore be used to determine both affinity and rate constants for interactions between various types of molecules. Here, we describe the application of a surface plasmon resonance biosensor for label-free investigation of the interaction between an immobilized antigen bovine serum albumin (BSA) and antibody rabbit anti-cow albumin IgG1 (anti-BSA). The formation of a self-assembled monolayer (SAM) over a gold surface is introduced into this laboratory training protocol as an effective immobilization method, which is very promising in biosensing systems based on detection of affinity interactions. In the next step, covalent attachment via artificially formed amide bonds is applied for the immobilization of proteins on the formed SAM surface. These experiments provide suitable experience for postgraduate students to help them understand immobilization of biologically active materials via SAMs, fundamentals of surface plasmon resonance biosensor applications, and determination of non-covalent biomolecular interactions. The experiment is designed for master and/or Ph.D. students. In some particular cases, this protocol might be adoptable for bachelor students that already have completed an extended biochemistry program that included a background in immunology. [source]