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Human Properdin Protein, Natural - 100 µg (CAT#: CB-P274-AB) Datasheet

Product Type
Human properdin (complement factor P) 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. HC2132 is purified from normal human serum.
100 µg
0.1 ml of approximately 1 mg/ml purified natural human Properdin isolated from healthy blood donors, in 10 mM Sodium phosphate, 145 mM NaCl, pH 7.3. The blood donors have been tested and found negative for various viruses (see table: Human blood test results"). The exact protein concentration is indicated on the label.
Functional studies, Immuno assays
Application Notes
Used for immune analysis and functional research. Compared with normal human serum standards, the functional activity is> 70%.
Storage Instructions
Product should be stored at -80°C. Repeated freeze and thaw cycles will cause loss of activity. Use C5 protein within 27 hours after thawing and keep on ice. Remainder amounts should be aliquoted and immediately re-freezed for future use. Aliquots should never be thawed more than once. Under recommended storage conditions, product is stable for at least one year.
Alternative Names
Complement factor P

All products and services are for Research Use Only. Do Not use in humans.


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