Proteins & Peptides

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 F(ab')2 purified protein is a proteolytic fragment of immunoglobulin G (IgG) obtained by limited digestion with the enzyme pepsin under controlled conditions of temperature, time and pH. Human IgG F(ab')2 molecules lack the Fc portion of Human IgG and therefore receptors that bind Human IgG Fc will not bind Human IgG F(ab')2 molecules.

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.

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 Rhodamine 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.

Collagen type I is the fibrillar collagen found in most connective tissues, including cartilage. Collagen type I is a protein that strengthens and supports many tissues in the body, including cartilage, bone, tendon, skin and the white part of the eye (sclera).

Human Collagen Type II is one of a family of proteins found particularly in the flesh and connective tissues of mammals (approximately one-third of the body's total protein). Over two dozen types of collagen have been described; Type II is found predominantly in hyaline cartilage (50% of the protein in hyaline is collagen type II) and is also found in the vitreous humor of the eye.

In muscle tissue, collagen serves as a major component of the endomysium. Collagen constitutes one to two percent of muscle tissue, and accounts for 6% of the weight of strong, tendinous muscles. A collagen may be defined as a protein containing sizable domain(s) of triple-helical conformation. Collagen type III, a fibrous scleroprotein found in bone, cartilage, tendon, bone marrow stroma and other connective tissue, yields gelatin on boiling. Collagen Type III scleroprotein is a simple protein found in horny and cartilaginous tissues and in the lens of the eye.