サポート ブログ Antibody Isotypes: IgG

Antibody Isotypes: IgG

Biointron 2024-01-20 Read time: 3 mins
IgG.jpg
Image credit: DOI: 10.1016/B978-0-12-374279-7.05002-5

Immunoglobulins, also known as antibodies, are heterodimeric proteins made up of two heavy (H) chains and two light (L) chains. They can be classified into five primary isotypes (IgG, IgA, IgD, IgE, and IgM) determined by the constant domains in their H chains, which give each isotype their different characteristics.

Immunoglobulin G is the most abundant subtype, being present in the largest concentrations at 75-80% of IgGs in blood and tissue fluids. IgG makes direct impacts on the immune response with high neutralization and opsonization activities towards toxins and viruses, acting as the first line of defense after memory B cells trigger a response. They are responsible for both existing and acquired immunity against previously encountered antigens. Once IgG binds to antigens, the Fc receptor can bind to macrophages, which can carry out phagocytosis on the intruder.1,2

Uniquely, IgG can also cross the placenta and impart immunity to the fetus. This occurs through transcytosis, in which the IgG is endocytosed and shuttled across the cytoplasm to be secreted towards the basal cell membrane of syncytiotrophoblasts. Once there, the complex is released into fetal circulation.

IgG can be further classified into: IgG1, IgG2, IgG3, and IgG4. All four subtypes exhibit different functional activities. For example, with a HIV patient, IgG3 antibodies have been demonstrated to be more effective at neutralizing HIV over IgG1, likely because of differing antibody flexibility affecting access and how changes are induced in the virus’ oligomer structure.3

At Biointron, we are dedicated to accelerating your antibody discovery, optimization, and production needs. Our team of experts can provide customized solutions that meet your specific research needs. Contact us to learn more about our services and how we can help accelerate your research and drug development projects.


References:

  1. Schroeder, H. W., & Cavacini, L. (2010). Structure and Function of Immunoglobulins. The Journal of Allergy and Clinical Immunology, 125(2 0 2), S41. https://doi.org/10.1016/J.JACI.2009.09.046 

  2. Borad, S. G., & Singh, A. K. (2022). Immunoglobulins. Encyclopedia of Dairy Sciences, 894–900. https://doi.org/10.1016/B978-0-12-818766-1.00367-6 

  3. Ciobanu, A. M., Dumitru, A. E., Gica, N., Botezatu, R., Peltecu, G., & Panaitescu, A. M. (2020). Benefits and Risks of IgG Transplacental Transfer. Diagnostics, 10(8). https://doi.org/10.3390/DIAGNOSTICS10080583 


Subscribe to our ブログ

Recent ブログ

The therapeutic efficacy of antibodies is closely related to their ability to recognize and bind specific epitopes on target antigens. Epitopes, or antigenic determinants, are a group of amino acids or other chemical groups that are part of a molecule to which an antibody attaches itself. Epitope characterization can help reveal the mechanism of antibody binding and apply intellectual property (patent) protection for novel antibodies, in addition to designing antibodies with high specificity and minimal cross-reactivity.

Jul 12, 2024
ブログ

Understanding the differences between antibody specificity and selectivity is essential for designing and interpreting antibody-based assays in research for experimental accuracy and data interpretation. Antibody specificity refers to an antibody's ability to recognize and bind to a particular epitope—a unique part of an antigen that elicits an immune response.

Jul 10, 2024
ブログ

Antibody-based assays are essential tools in biomedical research, providing the means to detect, quantify, and visualize specific proteins or antigens within complex biological samples. These assays' efficacy hinges on the antibodies' precise properties. While affinity, avidity, specificity, and selectivity are fundamental to antibody performance, the ultimate impact of these properties is heavily influenced by the experimental context in which the antibody is employed.

Jul 08, 2024
ブログ

Biologics, particularly antibodies, have become indispensable in biomedical research and therapeutic development. Research-use-only (RUO) biologics play a pivotal role in preclinical studies, providing researchers with the necessary tools to explore antibody functions and therapeutic potential in vivo.

Jul 04, 2024
ブログ

お客様の利便性を向上させるためにクッキーを使用しています。詳しくは プライバシーポリシー をご覧ください。