Complement Factor H ELISA Assay Kit
The Complement Factor H ELISA Assay Kit is For Research Use Only
Sizes: 1 x 96 wells
Sensitivity: 3.9 ng/mL
Dynamic Range: 3.9 – 250 ng/mL
Sample Size: 100 uL
Incubation Time: 2 hours 30 minutes
Sample Type: Serum, Plasma, Urine
Controls Not Included
The complement system mediates a number of essential biological functions that participate in host defense against infection, initiation of the inflammatory reaction, processing and clearance of immune complexes and regulation of the immune response.
There are three pathways of complement activation. The classical pathway is initiated by
immune complexes; the lectin pathway by surface bound mannan binding lectin; and the
alternative pathway by all the surfaces that are not specifically protected against it. Each generates a C3 convertase, a serine protease that cleaves the central complement protein C3, and generates the major cleavage fragment C3b. Complement factor H is a relatively abundant plasma protein, with a concentration of 400-800 μg/ml, that is essential to maintain complement homeostasis and to restrict the action of complement to activating surfaces. Factor H binds to C3b, acclerates the decay of the alternative pathway C3-convertase (C3bBb) and act as co-factor for the factor I-mediated proteolytic inactivation of C3b. Factor H regulates complement both in fluid phase and on cellular surfaces. Complement protein factor H is the first regulatory protein of the alternative pathway. Factor H is a single-chain serum glycoprotein of 150 kDa with a modular structure consisting of a tandem of 20 homologous units of about 60 amino acid, called short consensus repeats (SCR). Numerous functional sites have been identified along the 20 SCR domain structure of factor H. Three C3-binding sites have been identified; in the SCR1-4 in SCR6-10 and SCR13-20. Three polyanion binding sites like heparin and several glycoaminoglycans have also been identified in the SCR7, 13 and 20. Factor H displays anti-inflammatory functions and acts as a ligand for CRP. Factor H has two important functional domains that are located at the opposite ends of the protein. The N-terminal fragment of the factor H molecule is an essential fluid phase regulator of the alternative pathway. With the C terminal domain and SCR 7 factor H binds to cell and
tissue surface and thus mediates its protective role also on host cell surface. Genetic analyses reveal a clear association of complement factor H with different human diseases. These include diseases of the kidney, the atypical form of Hemolytic Uremic Syndrome (aHUS) and membraneoproliferative glomerulonephritis (MPGN), and of the eye, age-related macular degeneration (AMD).