NEW Product: The First Functional Properdin (Factor P) Assay

May 8th 2023

We are thrilled to present the latest additions to our Complement product range: two new Factor P assays – the quantitative Factor P assay and the first commercially available functional Factor P assay (Developed and Manufactured by Svar Life Science). Designed to work optimally together, these assays are ideal for assisting in the development of next-generation complement therapies!

Since the assays use the same capture antibody, you can directly relate the concentration and functionality of Properdin in your samples. Additionally, Factor P assays can be easily adapted for more in-depth studies, granting a closer look at the amplification loop of the complement system.

What is Factor P?

Factor P, also referred to as Properdin, has an important role in the amplification loop of the complement system. Upon binding to C3bBb, it acts as a stabilizer, extending the half-life of C3bBb significantly.

In addition, it inhibits the factor H-mediated cleavage of C3b by factor I, thereby increasing C3b formation and positively regulating the complement cascade response.

As an up-regulator of the complement system, properdin is of interest to pharmaceutical companies looking for therapeutic targets, as well as to academic groups studying the amplification loop.

Principle of the quantitative factor P assay

In the quantitative ELISA-based assay, the wells are coated with a capture antibody that binds to Factor P (FP) in the sample. An enzyme-conjugated detection antibody and a corresponding substrate are used to generate a signal corresponding to the properdin concentration in the sample.

Principle of the functional factor P assay

Factor P (FP) is bound by the same capture antibody in the functional assay as in the quantitative assay. A reference serum is then added. If the initial sample contains functional properdin, C3 from the reference will be cleaved to C3b. An enzyme-conjugated detection antibody is used to detect C3b in the well.

FOR RESEARCH USE ONLY. Not for use as a diagnostic tool or in the management of patients.

References:

Harboe, M. & Mollnes, T. E. The alternative complement pathway revisited. Journal of Cellular and Molecular Medicine 12, 1074–1084 (2008).
Harris, C. L. Expanding horizons in complement drug discovery: challenges and emerging strategies. Semin Immunopathol 40, 125–140 (2018).
Zelek, W. M., Xie, L., Morgan, B. P. & Harris, C. L. Compendium of current complement therapeutics. Molecular Immunology 114, 341–352 (2019).
McNamara, L. A. et al. High Risk for Invasive Meningococcal Disease Among Patients Receiving Eculizumab (Soliris) Despite Receipt of Meningococcal Vaccine. 66, (2017).