Basic concepts of immunoglobulin

Basic concepts of immunoglobulin

The reason why antiserum can react immunologically with the relevant antigen is because the antiserum contains the relevant antibody protein. It was originally believed that most antibodies are y-globulin and a small part is -beta globulin. Later, it was discovered that y-globulin is a glycoprotein with different primary immunochemical properties and extremely heterogeneous composition. Only part of the y-globulin has the ability of immunological binding. In order to accurately describe the properties of antibody globulin, it was proposed in the early 1960s that the globulin with antibody activity was called immunoglobulin. The immunoglobulin in antiserum is the product of plasma cells (monoclonal antibody is another matter). It exists not only in antiserum, but also in body fluids and exocrine fluids of organisms and on the membranes of lymphocytes. This immunoglobulin with antibody activity is composed of multiple components. Most of the immunoglobulins in human plasma exist in gamma globulin (y-globulin) and are divided into IgG, IgM, IgA, IgD, IgE and other components. Ig is the English abbreviation for Immunoglobulin, or immunoglobulin. Although immunoglobulin has many components, it is mainly IgG, which accounts for about 70% of human plasma gamma globulin, a molecular weight of about 150,000, a sedimentation coefficient of about 7S, and a sugar content of 2% -3%. In general, purified immunoglobulin refers to the purification of IgG. The enzyme-labeled IgG is obtained by cross-linking the enzyme and IgG through a bifunctional reagent, which is usually called an enzyme-labeled antibody. Therefore, it is necessary to further understand the chemical structure and genetic structure of IgG. In short, antibodies are concepts of biological function, while immunoglobulins are concepts of chemical structure. All antibodies are immunoglobulins, but not all immunoglobulins are antibodies.