靶点/蛋白质:The gene for properdin is X-linked and resides on the short arm of the X chromosome between Xp11.3-Xp11.23. The gene is 6 kb is size with 10 exons. Accession numbers: Human (X70872, X70872.1, X57748, M83652, S49355), Mouse (X12905), Guinea pig (S81116).
来源:Normal human serum (shown by certified tests to be negativefor HBsAg, HTLV-I/II, STS, and for antibodies to HCV, HIV-1 and HIV-II).
存储溶液:10 mM Sodium phosphate, 145 mM NaCl, pH 7.3
参考文献:Hartmann, S. and Hofsteenge, J. (2000) Properdin, the positive regulator of complement, is highly C-mannosylated. J. Biol. Chem. 275:28569-74. Kemper C. and Hourcade D.E. (2008) Properdin: New roles in pattern recognition and target clearance. Mol. Immunol. 45, 4048-4056. Law, S.K.A. and Reid, K.B.M. (1995) Complement 2nd Edition (ISBN 0199633568) Oxford University Press, Oxford. Morley, B.J. and Walport, M.J. (2000) The Complement Facts Book (ISBN 0127333606) Academic Press, London. Morgan, B.P. ed. (2000) Complement Methods and Protocols. Humana Press. Nolan, K.F. and Reid, K.B.M. (1993) Methods in Enzymology 223:35-46. Pangburn, M.K. (1989) Analysis of the natural polymeric forms of human properdin and their functions in complement activation. J.Immunol. 142:202-207. Pangburn, M.K., (1988) Alternative pathway of complement. Methods in Enzymology 162:639-653. Smith, C.A., Pangburn, M.K., Vogel, C.W. and Muller-Eberhard, H.J. (1984) J. Biol. Chem. 259:4582-4588.
应用:CVF has been widely used in animal studies to examine the role of the complement system in disease. Purified CVF has been injected i.p. or i.v. into many animal models (and even humans) to systemically inactivate the complement system for 3-6 days (Morgan B.P. (1990); Vogel, C-W. and Muller-Eberhard, H.J. (1984); von Zabern, I. (1993)). The treatment with CVF from the cobra species naja naja kaouthia depletes both C5 and C3. The typical level required for effective complement suppression is 0.5- 1.0 μg CVF/g body weight (Vogel, C-W. and Muller-Eberhard, H.J. (1984); von Zabern, I. (1993)). Effective doses that have been used are 10 μg CVF/20 g mouse, 80 μg/150 g rat, 150 μg/225 g guinea pig, and 1200 to 3000 μg/3 kg rabbit to reduce complement titers to less than 5% of normal. Subsequent injections are less effective due to immune responses to CVF so maintaining complement suppression for longer periods is impossible. De-complemented animals have been shown to have numerous impaired immune functions, but after a week complement titers begin to return to normal and are fully restored after 10 days (von Zabern, I. (1993)).A cautionary note: many reports of CVF use in animals cite the amount used as Units/kg. Also, it is often sold as Units/mL. Unfortunately, there are many different types of “Units” and they vary more than 10-fold. Unless the source describes the assay used, the Units/kg must be considered as uncertain and irreproducible. CVF is extremely stable and in our experience the complement-consuming activity/mg does not vary significantly from year-to-year or lot-to-lot. Thus, the above cited amounts for in vivo use are the best representation of what has been used successfully by the majority of published studies. Each lot comes with a Certificate of Analysis giving the Units/mg and this should be used along with the mg administered when publishing results.
商品关键词:Complement Factor P (Properdin),A139,CompTech
简单描述:Complement factor P (properdin) is purified from normal human serum. Factor P is a 53,000 dalton cationic protein that circulates in blood in the form of dimers, trimers and tetramers. It binds rapidly to C3b on surfaces where complement has begun to activate. Properdin binds most avidly to C3b,Bb the alternative pathway C3/C5 convertase, but also binds to C3b < C3b,B < C3b,Bb. Its primary function is to stabilize the C3b,Bb complex allowing increased alternative pathway activation (Pangburn, M.K., (1988); Nolan, K.F. and Reid, K.B.M. (1993)). Properdin enhances formation of the alternative pathway C3 convertase by increasing binding of factor B to P,C3b complexes. Thus, properdin is an accelerator (positive regulator) of complement activation. Properdin has recently been proposed to be able to also initiate activation of the alternative pathway by binding to the target surface and initiating C3/C5 convertase formation (Kemper C. and Hourcade D.E. (2008)).
Concentration: 1.0 mg/mL (see Certificate of Analysis for actual concentration)
Form: Frozen liquid
Activity: >70% versus normal human serum standard
Purity: >90% by SDS-PAGE
Extinction Coeff: A280 nm = 1.78 at 1.0 mg/mL
Molecular Weight: 53,000 Da (single chain)
Preservative: None, 0.22 µm filtered.
Physical Characteristics & Structure: The basic subunit of this protein is a 53,000 dalton single chain molecule which is composed of six thrombospondin-like repeat (TSR) domains. These basic units are linked at the ends (C-terminal to N-terminal) to form circular dimers, trimers, tetramers and perhaps higher forms in blood (Pangburn, M.K. (1989)). Electron microscopic images (Smith, C.A. et al. (1984)) have clearly demonstrated these structures. Higher oligomers of properdin are formed upon freeze thaw and perhaps during complement activation and were originally called “activated” properdin due to their enhanced ability to bind and activate complement. Properdin has a rare post-translational modification in that its tryptophan residues are highly mannosylated (Hartmann, S. and Hofsteenge, J. (2000)). There is also a single N-linked glycosylation site near the C-terminal. These contribute to a carbohydrate content estimated at 10%. Properdin is highly positively charged at neutral pH and has a pI greater than 9.5. It is one of the most positively charged proteins in blood (Morley, B.J. and Walport, M.J. (2000)).
EC Number: EC 3.4.21.45
Function: Properdin binds most avidly to C3b,Bb the alternative pathway C3/C5 convertase, but also binds to C3b < C3b,B < C3b,Bb. Its primary function is to stabilize the C3b,Bb complex allowing increased alternative pathway activation. Properdin enhances formation of the alternative pathway C3 convertase by increasing binding of factor B to P,C3b complexes. Thus, properdin is an accelerator (positive regulator) of complement activation.
Assays: Assays depend on the ability of properdin to bind to clusters of C3b or to accelerate the activation of the alternative pathway. ELISA assays for protein may be performed by coating plates with excess C3b (CompTech Cat# A114), binding properdin and detection with goat anti-Properdin (CompTech Cat# A239). Functional assays are best performed using P-depleted serum (CompTech Cat# A339) and then measuring the accelerated lysis of rabbit erythrocytes (CompTech Cat# B300) in the presence of properdin (CompTech Cat# A139) and MgEGTA (CompTech Cat# B106). Lysis does occur slowly in the absence of properdin so these assays must be timed assays to compare the rates of lysis with and without properdin. Assays for “activated” properdin consist of incubating properdin in NHS for extended periods of time (30 to 60 min) and measuring the residual C3 activity using C3-depleted serum (CompTech Cat# 313) and rabbit erythrocytes.
In vivo: Blood contains approximately 5 µg/mL properdin (Pangburn, M.K. (1989)). Properdin does not appear to be synthesized in the liver where most complement proteins are synthesized. It is primarily made by monocytes, T-cells and neutrophils. In neutrophils it is stored in granules that release the properdin in response to C5a, FMLP, IL8 and TNF-alpha.
Regulation : See In vivo above.
Deficiencies: Deficiencies are rare and can be the result of a total lack of properdin protein in blood or the presence of immunochemically detectable, but functionally inactive properdin.
Diseases: Deficiency of properdin results in recurrent fulminant meningococcal infections. Neisserial infections typically occur in young males, progress rapidly and can be fatal. Reoccurrences are rare probably due to the generation of protective antibodies during the first incident.
Precautions/Toxicity/Hazards: This protein is purified from human serum, therefore precautions appropriate for handling any blood-derived product must be used even though the source was shown by certified tests to be negative for HBsAg, HTLV-I/II, STS, and for antibodies to HCV, HIV-1 and HIV-II.
Hazard Code: B WGK Germany 3MSDS available upon request.