Other Proteins

Immunoglobulin A is the primary responder in muscosal immunity, and comprises close to 75% of the total immunoglobulin produced. IgA can also be secreted and is protected from degradation by many proteolytic enzymes (which allows it to be secreted along the gastrointestinal tract). Immunoglobulin A only weakly activates the complement system and is not readily opsonized.

Immunoglobulin M is the largest antibody isotype and the first to be secreted against an initial exposure to antigen. IgM is predominantly produced in the spleen. Formed from covalently linking 5 immunoglobulins together, the approximate molecular weight of IgM is 900kDa and possesses 10 binding sites (though due to the size of most antigens, not all sites are capable of binding at once). Due to this large size, IgM is typically isolated to the serum.

Human IgM Fab mu Biotin is ideal for investigators involved in serum protein component research. IgM is by far the physically largest antibody in the human circulatory system. It is the first antibody to appear in response to initial exposure to antigen. The spleen is the major site of specific IgM production. Distinct heavy chains differ in size and composition; alpha and gamma contain approximately 450 amino acids, while μ and ε have approximately 550 amino acids.

Human IgM (myeloma) Fc5µ fragment Biotin conjugate consists of only the µ (mu) chain of the Fc fragment. Immunoglobulin M is the largest antibody isotype and the first to be secreted against an initial exposure to antigen. IgM is predominantly produced in the spleen. IgM is formed from covalently linking 5 immunoglobulins together. Due to this large size, IgM is typically isolated to the serum.

Human albumin or serum albumin is encoded by the ALB gene and is the most abundant plasma protein in mammals. Human albumin is essential for maintaining the osmotic pressure needed for proper distribution of body fluids between intravascular compartments and body tissues. Human albumin also acts as a plasma carrier by non-specifically binding several hydrophobic steroid hormones and as a transport protein for hemin and fatty acids. Too much serum albumin in the body can be harmful.

Human transferrin is encoded by the TF gene and is an iron-binding blood plasma glycoprotein that controls the level of free iron in biological fluids. Human transferrin binds iron very tightly but reversibly. Human transferrin is the most important iron pool in mammals. Human transferrin has a molecular weight of around 80 kDa and contains 2 specific high-affinity Fe(III) binding sites. The affinity of Human transferrin for Fe(III) is extremely high but decreases progressively with decreasing pH below neutrality. Human Transferrin also plays a role in the immune system, creating environments low in iron for which many pathogenic bacteria are unable to thrive.

Human IgG purified protein (Immunoglobulin G) are antibody molecules. Human IgG is composed of four peptide chains — two heavy chains gamma and two light chains. Human IgG has two antigen binding sites. Other Immunoglobulins may be described in terms of polymers with the IgG structure considered the monomer. Human IgG typically constitutes 75% of serum immunoglobulins. Human IgG molecules are synthesized and secreted by plasma B cells.

Human IgG Fc purified protein is a proteolytic fragment of immunoglobulin G (IgG) obtained by limited digestion with the enzyme papain under controlled conditions of temperature, time and pH. Receptors bind the Fc portion of Human IgG and often this fragment is removed from immunoglobulins to minimize receptor binding and lower background reactivity.

Secreted as part of the adaptive immune response by plasma B cells, immunoglobulin G constitutes 75% of serum immunoglobulins. Immunoglobulin G binds to viruses, bacteria, as well as fungi and facilitates their destruction or neutralization via agglutination (and thereby immobilizing them), activation of the compliment cascade, and opsinization for phagocytosis. The F(ab) fragment is the portion of the antibody that binds to the antigen target. The immunoglobulin Fab also possesses one constant and one variable region of both the heavy and light chain.