The antigen binding sites of various hCG monoclonal antibodies show homology to different domains of LH receptor

2007 ◽  
Vol 260-262 ◽  
pp. 23-32 ◽  
Author(s):  
Rupali A. Gadkari ◽  
S. Sandhya ◽  
R. Sowdhamini ◽  
Rajan R. Dighe
Keyword(s):  
Monoclonal Antibodies ◽  
Binding Sites ◽  
Antigen Binding ◽  
Lh Receptor

scholarly journals Preferential Binding of Anti-Neutrophil Cytoplasmic Antibodies to an Unexpected Epitope of a Chimeric Proteinase 3 Mutant

2019 ◽  
Author(s):  
Marta Casal Moura ◽  
Gwen E. Thompson ◽  
Darlene A. Nelson ◽  
Lynn A. Fussner ◽  
Amber M. Hummel ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Binding Sites ◽  
Granulomatosis With Polyangiitis ◽  
Antigen Binding ◽  
Proteinase 3 ◽  
Necrotizing Vasculitis ◽  
Novel Treatment ◽  
Preferential Binding ◽  
Major Antigen

AbstractProteinase 3 (PR3) is the major antigen for anti-neutrophil cytoplasmic antibodies (ANCAs) in the systemic autoimmune vasculitis, granulomatosis with polyangiitis (GPA). PR3-targeting ANCAs (PR3-ANCAs) recognize different epitopes on PR3 and are thought to be pathogenic for the development of the necrotizing vasculitis. To identify epitopes recognized by PR3-ANCAs, we pursued a strategy based on human-murine chimeric PR3 mutants. Interestingly, rather than observing reduced binding of PR3-ANCAs to Epitope 5 on a PR3 mutant (iHm5-Val103) with chimeric mutations in Epitope 5, we found substantially increased binding of the majority of PR3-ANCAs to iHm5-Val103 compared with the PR3 mutant (iPR3-Val103) clinically used to detect PR3-ANCAs. More interestingly, using iHm5-Val103 we identified a monoclonal antibody (moANCA518) from a patient with GPA that bound selectively to iHm5-Val103. Inhibition experiments using epitope-specific monoclonal antibodies and their antigen-binding fragments mapped the binding sites of moANCA518 and PR3-ANCAs (from patients displaying preferential binding to iHm5-Val103 over iPR3-Val103) to Epitope 3 on iHm5-Val103, a mutation-free epitope located far from the mutation sites in Epitope 5. These results demonstrate that the selective binding of moANCA518 (and likely the preferential binding of PR3-ANCAs from patients) to iHm5-Val103 is conferred by increased antigenicity of Epitope 3 on iHm5-Val103 caused by distal mutations, indicating that PR3-ANCAs bind to epitopes of a folded antigen conducive to allosteric effects of mutations—a previously unrecognized characteristic with implications for studying antibody-mediated autoimmune diseases and novel treatment approaches.

scholarly journals Is SARS-CoV-2 Neutralized More Effectively by IgM and IgA than IgG Having the Same Fab Region?

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 751
Author(s):  
Yalcin Pisil ◽  
Zafer Yazici ◽  
Hisatoshi Shida ◽  
Tomoyuki Miura
Keyword(s):  
Monoclonal Antibodies ◽  
Binding Sites ◽  
Spike Protein ◽  
Antigen Binding ◽  
Kidney Cells ◽  
Host Cell Line ◽  
Multiple Antigen ◽  
Viral Particles ◽  
New Generation ◽  
Neutralization Ability

Recently, recombinant monoclonal antibodies (mAbs) of three Ig isotypes (IgG, IgA, and IgM) sharing the same anti-spike protein Fab region were developed; we evaluated their neutralizing abilities using a pseudo-typed lentivirus coated with the SARS-CoV-2 spike protein and ACE2-transfected cat Crandell–Rees feline kidney cells as the host cell line. Although each of the anti-SARS-CoV-2 mAbs was able to neutralize the spike-coated lentiviruses, IgM and IgA neutralized the viral particles at 225-fold and 125-fold lower concentrations, respectively, than that of IgG. Our finding that the neutralization ability of Igs with the same Fab domain was dramatically higher for IgM and IgA than IgG mAbs suggests a strategy for developing effective and affordable antibody therapies for COVID-19. The efficient neutralization conferred by IgM and IgA mAbs can be explained by their capacity to bind multiple virions. While several IgG mAbs have been approved as therapeutics by the FDA, there are currently no IgM or IgA mAbs available. We suggest that mAbs with multiple antigen-binding sites such as IgM and IgA could be developed as the new generation of therapy.

Aggregation prone regions in antibody sequences raised against Vibrio cholerae: A bioinformatic approach

2020 ◽  
Vol 15 ◽  
Author(s):  
Zakia Akter ◽  
Anamul Haque ◽  
Md. Sabir Hossain ◽  
Firoz Ahmed ◽  
Md Asiful Islam
Keyword(s):  
Vibrio Cholerae ◽  
Binding Sites ◽  
Bioinformatic Analysis ◽  
Antigen Binding ◽  
Short Term ◽  
Protein Database ◽  
The Stability ◽  
Bioinformatic Approach ◽  
Self Aggregation ◽  
Complementarity Determining Region

Background: Cholera, a diarrheal illness causes millions of deaths worldwide due to large outbreaks. Monoclonal antibody used as therapeutic purposes of cholera are prone to be unstable due to various factors including self-aggregation. Objectives: In this bioinformatic analysis, we identified the aggregation prone regions (APRs) of different immunogens of antibody sequences (i.e., CTB, ZnM-CTB, ZnP-CTB, TcpA-CT-CTB, ZnM-TcpA-CT-CTB, ZnP-TcpA-CT-CTB, ZnM-TcpA, ZnP-TcpA, TcpA-CT-TcpA, ZnM-TcpA-CT-TcpA, ZnP-TcpA-CT-TcpA, Ogawa, Inaba and ZnM-Inaba) raised against Vibrio cholerae. Methods: To determine APRs in antibody sequences that were generated after immunizing Vibrio cholerae immunogens on Mus musculus, a total of 94 sequences were downloaded as FASTA format from a protein database and the algorithms such as Tango, Waltz, PASTA 2.0, and AGGRESCAN were followed to analyze probable APRs in all of the sequences. Results: A remarkably high number of regions in the monoclonal antibodies were identified to be APRs which could explain a cause of instability/short term protection of anticholera vaccine. Conclusion: To increase the stability, it would be interesting to eliminate the APR residues from the therapeutic antibodies in a such way that the antigen binding sites or the complementarity determining region loops involved in antigen recognition are not disrupted.

scholarly journals Generation of Monoclonal Antibodies for Sensitive Detection of Pro-Inflammatory Protein S100A9

2021 ◽  
Vol 11 (10) ◽  
pp. 4659
Author(s):  
Eun-Jung Kim ◽  
Gyu-Min Im ◽  
Chang-Soo Lee ◽  
Yun-Gon Kim ◽  
Byoung Joon Ko ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Calcium Binding ◽  
Nucleotide Sequences ◽  
Antibody Fragments ◽  
High Yield ◽  
Antigen Binding ◽  
Hybridoma Cell Culture ◽  
Inflammatory Protein ◽  
Inflammatory Processes ◽  
Yield And Purity

The calcium-binding protein S100A9 regulates inflammatory processes and the immune response. It is overexpressed in a variety of inflammatory and oncologic conditions. In this study, we produced a recombinant human S100A9 (hS100A9) antigen with high yield and purity and used it to generate a hybridoma cell culture-based monoclonal anti-hS100A9 antibody. We selected five anti-hS100A9 antibodies from cell supernatants that showed high antigen binding efficiency and identified the nucleotide sequences of three antibodies: two with high effective concentration values and one with the lowest value. The antigen and antibody development procedures described herein are useful for producing large amounts of monoclonal antibodies against hS100A9 and other antigens of interest. The nucleotide sequences of the anti-hS100A9 monoclonal antibody revealed herein will be helpful in the generation of recombinant antibodies or antibody fragments against hS100A9.

scholarly journals Production of Recombinant Monoclonal Antibodies in the Egg White of Gene-Targeted Transgenic Chickens

Genes ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 38
Author(s):  
Takehiro Mukae ◽  
Sho Okumura ◽  
Takuma Watanobe ◽  
Kyoko Yoshii ◽  
Takahiro Tagami ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Binding Capacity ◽  
Specific Binding ◽  
Egg White ◽  
Peptide Sequence ◽  
Efficient Production ◽  
Antigen Binding ◽  
Transgenic Chicken ◽  
Bioreactor System ◽  
Transgenic Chickens

Increased commercial demand for monoclonal antibodies (mAbs) has resulted in the urgent need to establish efficient production systems. We previously developed a transgenic chicken bioreactor system that effectively produced human cytokines in egg whites using genome-edited transgenic chickens. Here, we describe the application of this system to mAb production. The genes encoding the heavy and light chains of humanized anti-HER2 mAb, linked by a 2A peptide sequence, were integrated into the chicken ovalbumin gene locus using a CRISPR/Cas9 protocol. The knock-in hens produced a fully assembled humanized mAb in their eggs. The mAb expression level in the egg white was 1.4–1.9 mg/mL, as determined by ELISA. Furthermore, the antigen binding affinity of the anti-HER2 mAb obtained was estimated to be equal to that of the therapeutic anti-HER2 mAb (trastuzumab). In addition, antigen-specific binding by the egg white mAb was demonstrated by immunofluorescence against HER2-positive and -negative cells. These results indicate that the chicken bioreactor system can efficiently produce mAbs with antigen binding capacity and can serve as an alternative production system for commercial mAbs.

scholarly journals Novel idiotypic and antigen-binding characteristics in two anti-dinitrophenyl monoclonal antibodies.

1977 ◽  
Vol 146 (1) ◽  
pp. 282-286 ◽  
Author(s):  
N H Sigal
Keyword(s):  
Monoclonal Antibodies ◽  
Germ Line ◽  
Hypervariable Region ◽  
Weight Basis ◽  
Antigen Binding ◽  
The Novel ◽  
Maximum Frequency ◽  
Somatic Variant ◽  
Binding Characteristics ◽  
Cell Pool

Monoclonal anti-dinitrophenyl antibodies generated in the splenic focus system from B cells of adult BALB/c mice were studied for the presence or absence of murine anti-T15 (M anti-T15) reactivity and for their ability to bind phosphorylcholine (PC). Two foci of the 680 clones analyzed bound PC, and one of these antibodies reacted with M anti-T15 and anti-Fab on a 1:1 weight basis. The discovery of a clonotype reactive with M anti-15 but not with rabbit anti-T15 (R anti-T15) serum, the converse of the R anti-T15+, M anti-T15- clonotype identified in the PC-specific repertoire, points to the novel idiotypic relationships which may be found among homogeneous antibodies binding diverse antigens. The R anti-T15-, M anti-T15+ clonotype may represent a distinct set of hypervariable region sequences inserted into the T15 framework or may be a somatic variant of the T15 germ-line sequence. In addition, the maximum frequency with which this clonotype occurs within the B-cell pool is estimated.

THE MOLECULAR ORGANIZATION OF HUMAN ALPHA 2-MACROGLOBULIN. AN IMMUNO ELECTRON MICROSCOPIC STUDY WITH MONOCLONAL ANTIBODIES

1987 ◽  
Author(s):  
E Delain ◽  
M Barrav ◽  
J Tapon-Bretaudière ◽  
F Pochon ◽  
F Van Leuven
Keyword(s):  
Monoclonal Antibodies ◽  
Binding Sites ◽  
Divalent Cations ◽  
The Other ◽  
Molecular Organization ◽  
Cellular Receptor ◽  
Electron Microscopic ◽  
Microscopic Method ◽  
Bait Region ◽  
Electron Microscopic Method

Electron microscopy is a very convenient method to localize the epitopes of monoclonal antibodies (mAbs) at the surface of macromolecules for studying their tree-dimensional organization.We applied this immuno-electron microscopic method to human ct2-macroglobulin (ct2M). 29 anti-α2M mAbs have been tested with the four different forms of a2M : native and chymotrypsin-transformed tetramers, and the corresponding dimers, obtained by dissociation with divalent cations. These mAbs can be classified in three types : those which are specific for 1) the H-like transformed molecules, 2) the native molecules, and 3) those which can react with both forms of α2M.1) Among the H-like α2M specific mAbs, several react with the 20 kD-domain which is recognized by the cellular receptor of transformed a2M. This domain is located at the carboxyterminal end of each monomer. One IgG binds to the end of two adjacent tips of the H-like form.The other mAbs of this type bind to the α2M tips at non-terminal positions. Intermolecular connections built polymers of alternating α2M and IgG molecules.2) Among the native a2M-specific mAbs some are able to inhibit the protease-induced transformation of the native α2M. The binding sites of these mAbs are demonstrated on the native half-molecules. One of these mAbs was also able to react with transformed dimers, in a region corresponding very likely to an inaccessible epitope in the tetrameric transformed α2M molecule.3) Among the mAbs of this type, only two were able to inhibit the protease-induced transformation of α2M. Obviously, their epitopes should be close to the bait region of α2M. The other mAbs reacting with both α2M forms did not inhibit the α2M transformation.All these mAbs can be distinguished by the structure of the immune complexes formed with all forms of α2M. The epitopes are more easily located on the dimers and on the H-like transformed α2M than on the native molecules.From these observations, we propose a new model of the tree-dimensional organization of the human α2M in its native and transformed configurations, and of its protease-induced transformation.

scholarly journals Predominant VH genes expressed in innate antibodies are associated with distinctive antigen-binding sites

1999 ◽  
Vol 96 (5) ◽  
pp. 2262-2267 ◽  
Author(s):  
K. J. Seidl ◽  
J. A. Wilshire ◽  
J. D. MacKenzie ◽  
A. B. Kantor ◽  
L. A. Herzenberg ◽  
...  
Keyword(s):  
Binding Sites ◽  
Antigen Binding ◽  
Vh Genes ◽  
Innate Antibodies

scholarly journals Inhibition of acanthamoeba actomyosin-II ATPase activity and mechanochemical function by specific monoclonal antibodies.

1984 ◽  
Vol 99 (3) ◽  
pp. 1024-1033 ◽  
Author(s):  
D P Kiehart ◽  
T D Pollard
Keyword(s):  
Monoclonal Antibodies ◽  
Atpase Activity ◽  
Conformational Changes ◽  
Binding Sites ◽  
Polyclonal Antibodies ◽  
Myosin Ii ◽  
Antigenic Site ◽  
Actin Binding ◽  
Filamentous Form ◽  
Antibody Effects

Monoclonal and polyclonal antibodies that bind to myosin-II were tested for their ability to inhibit myosin ATPase activity, actomyosin ATPase activity, and contraction of cytoplasmic extracts. Numerous antibodies specifically inhibit the actin activated Mg++-ATPase activity of myosin-II in a dose-dependent fashion, but none blocked the ATPase activity of myosin alone. Control antibodies that do not bind to myosin-II and several specific antibodies that do bind have no effect on the actomyosin-II ATPase activity. In most cases, the saturation of a single antigenic site on the myosin-II heavy chain is sufficient for maximal inhibition of function. Numerous monoclonal antibodies also block the contraction of gelled extracts of Acanthamoeba cytoplasm. No polyclonal antibodies tested inhibited ATPase activity or gel contraction. As expected, most antibodies that block actin-activated ATPase activity also block gel contraction. Exceptions were three antibodies M2.2, -15, and -17, that appear to uncouple the ATPase activity from gel contraction: they block gel contraction without influencing ATPase activity. The mechanisms of inhibition of myosin function depends on the location of the antibody-binding sites. Those inhibitory antibodies that bind to the myosin-II heads presumably block actin binding or essential conformational changes in the myosin heads. A subset of the antibodies that bind to the proximal end of the myosin-II tail inhibit actomyosin-II ATPase activity and gel contraction. Although this part of the molecule is presumably some distance from the ATP and actin-binding sites, these antibody effects suggest that structural domains in this region are directly involved with or coupled to catalysis and energy transduction. A subset of the antibodies that bind to the tip of the myosin-II tail appear to inhibit ATPase activity and contraction through their inhibition of filament formation. They provide strong evidence for a substantial enhancement of the ATPase activity of myosin molecules in filamentous form and suggest that the myosin filaments may be required for cell motility.

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