The largest immunoglobulin, composed of five Y-shaped units held together by a J polypeptide chain. It is the third highest serum immunoglobulin and serves as the first Ig produced in response to an antigen.
The least common serum immunoglobulin, primarily involved in allergic reactions.
Osmotic pressure is the pressure exerted by proteins in blood plasma that pulls water into the circulatory system; a decrease in plasma proteins leads to reduced osmotic pressure and fluid retention in tissue spaces, causing edema.
Two identical heavy chains and two identical light chains, connected by disulfide bonds and stabilized by salt linkages, hydrogen, and hydrophobic bonds.
The Mannose-Lectin Pathway is activated by mannose binding lectin binding to mannose residues on the pathogen surface, which activates MBL-associated serine proteases (MASP-1 and MASP-2) to form C3 convertase (C4a2b).
A protein found on the surface of certain cells (NK cells, macrophages, neutrophils, and mast cells) that binds to antibodies attached to infected cells or invading pathogens, stimulating phagocytic or cytotoxic cells to destroy microbes or infected cells.
Albumin binds to and transports numerous ligands such as free fatty acids, calcium, hormones, bilirubin, copper, and tryptophan, and carries bile acids recycled from the intestine to the liver.
B Lymphocytes (B cells) from bone marrow, T Lymphocytes (T cells) from thymus, and components of the innate immune system.
Haptoglobin is a glycoprotein that binds free hemoglobin during hemolysis, preventing its loss into urine, and exists in three polymorphic forms which can help diagnose hemolytic anemia.
Transferrin is a glycoprotein that transports iron in plasma as ferric ions (Fe3+) and protects the body against the toxic effects of free iron, facilitating cellular uptake of iron.
Glycoprotein molecules produced by plasma cells in response to an immunogen, functioning as antibodies against invaders.
Plasma proteins are primarily glycoproteins synthesized in the liver, rich in disulfide bonds, and include fibrinogen and clotting factors, with a characteristic half-life in circulation.
Ceruloplasmin is a copper-containing glycoprotein that carries 90% of plasma copper and has oxidase activity, playing a crucial role in copper metabolism and transport.
The second highest serum immunoglobulin, which can be oligomeric (comprised of 2-4 IgA) or monomeric, includes a 15KD joining chain (J chain) and a 70KD secretory component chain, and is involved in mucosal or local immunity.
A major component of acute phase proteins that reacts with the C polysaccharide of pneumococci, promoting the immune system through complement cascade activation, rising significantly during acute inflammation.
Albumin is the most abundant protein in blood plasma, consisting of a single polypeptide chain with 585 amino acids and 17 disulfide bonds, synthesized by the liver, and has a half-life of 20 days.
C3b is a large fragment produced by the cleavage of C3, which oxidizes microbial pathogens and promotes opsonization and killing of bacteria.
The most abundant class of immunoglobulin (80%), consisting of four subclasses (IgG1, IgG2, IgG3, and IgG4), all of which are monomers. Subclasses differ in the number of disulfide bonds and the length of the hinge region, with IgG3 having the longest hinge.
IgM cannot transverse blood vessels and is restricted to the bloodstream. It is a good complement activator and binds to Fc receptors, serving as the first line of defense in a primary immune response.
Plasma is the clear, straw-colored liquid component of blood that makes up 55% of total blood volume, containing serum and clotting factors, and carries platelets, RBCs, and WBCs.
Globulins include antibodies (gamma globulins) and glycoproteins, synthesized in the liver and lymphoid tissues, and assist in blood clotting and transport proteins through lipoproteins.
Globulins are a major fraction of plasma proteins, distributed into alpha1, alpha2, beta, and gamma globulins, and account for 65-85 g/l in plasma.
C5a attracts macrophages and neutrophils, and activates mast cells, playing a crucial role in promoting inflammation.
IgA is the major secretory immunoglobulin found in body secretions such as tears, breast milk, saliva, and mucus. It is the most predominant antibody in colostrum, does not activate complement unless aggregated, and binds to Fc receptors on some cells.
The functions of blood include respiration (transporting O2 and CO2), nutrition (transporting food), excretion (removing waste), regulatory functions (water content and body temperature), defense (antibodies and white blood cells), acid-base balance, hormone transport, and coagulation.
The Classical Pathway involves complement components C1, C2, and C4, and is triggered by antigen-antibody complex binding to C1, forming C3 convertase (C4b2a) which splits C3 into C3b and C3a.
The Alternative Pathway is triggered by various factors (B, D, H) interacting with C3b, promoting an amplification loop in the presence of bacterial and fungal cell walls.
IgG is the major immunoglobulin in extravascular spaces, facilitates placental transfer (the only class that crosses the placenta), activates complement, and binds to cells such as macrophages, monocytes, PMNs, and some lymphocytes that have Fc receptors for its Fc region.
An immunoglobulin present in very low levels in serum (<1%), with a basic monomer structure. It is found on the surface of circulating B lymphocytes and is often co-expressed with IgM.
Plasma proteins that change during inflammation, infection, injury, or cancer, serving as indicators of inflammation with sensitive but non-specific plasma concentration changes.
Blood plasma consists of 90% water, 6 to 8% plasma proteins, and 1% electrolytes, along with nutrients, hormones, and other components.
IgG, IgA, IgM, IgE, and IgD, each associated with different types of heavy chains.
