Immunoglobulin-binding protein

Content sourced from Wikipedia, licensed under CC BY-SA 3.0.

Immunoglobulin-binding proteins are any proteins that attach to antibodies (immunoglobulins). They form a broad group because many different proteins can bind antibodies. These proteins may latch onto different parts of an antibody and can work with antibodies from various species. Many come from bacteria, which use them to capture antibodies and sometimes to help survive the immune response. Common examples include Protein A from Staphylococcus aureus and Protein G from Streptococcus species, which bind the Fc part of IgG, and Protein L from Peptostreptococcus magnus, which binds light chains. In the lab, these proteins are used to purify antibodies or to block antibodies in tests, making them useful tools for research and diagnostics.