Anti-Human Properdin Monoclonal Antibody (clone SIM 295-9.3.4) -100 µg (CAT#: CB-P171-AB) Datasheet

Antibody

The monoclonal antibody SIM 295-9.3.4 reacts with human properdin (P factor), which is a single-chain plasma glycoprotein with an apparent molecular weight of 52-55 kDa. The protein domain structure of properdin consists of six thrombospondin repeats between the short N- and C-terminal domains​​. In the blood, properdin exists as a mixture of head and tail dimers, trimers and tetramers. The protein is expressed by a variety of white blood cells, including monocytes, T lymphocytes and neutrophils, but it is also expressed by endothelial cells, where certain stress factors induce properdin synthesis. Properdin participates in alternative pathways of complement activation by extending the half-life of unstable C3bBb (which is deposited on the surface of immune complexes or foreign bodies), along with C3 and factors B, D, I and H. This allows the formation of C3bBb to be amplified in the competition between factor I and C3b catabolism using factor H as a cofactor. The local amplification process leads to the production of the alternative pathway C5 convertase C3bBb3b and initiates the terminal pathway of complement activation. As a result, properdin is consumed by binding to C3bBb, which indicates the order of tetramers in preference to trimers rather than dimers, which corresponds to the functional activity of the oligomeric form. Depending on the exact nature of the defect, the lack of molecules or functional abnormalities may cause serious damage to the activation of alternative pathways. So far, three types of defects have been described: Type 1 (or type I) is characterized by very low or non-existent serum properdin activity in the hemolysis assay, and serum immune active protein <0.1 off/ml; 2 Type (or type II) is characterized by low levels of immunoreactive protein but detectable (> 2 off g/ml), some (but not all) functional tests are impaired, type 3 (or type III) immunoreactive protein The level is normal, but dysfunctional (5-25 off g/mL). Compared with the non-diabetic control group, lower properdin levels were found in 70% of diabetic patients, indicating that the authors believe that patients with low properdin expression should take preventive measures and early infection prevention measures. The monoclonal antibody SIM 295-9.3.4 is suitable for flow cytometry, immunohistochemistry, western blot and immunoassay.

Autoimmunity