Complement Factor B Functional Test

Overview of Complement Factor B Functional Test

Regulation of complement system activity holds paramount significance in maintaining organismal homeostasis, relying upon the dynamic assembly and disassembly of pivotal convertase complexes.

Complement factor B (FB), a pivotal 95-kDa protein, assumes a critical role as a catalytic component within the context of the alternative pathway (AP) of the complement system. The enzymatic activation turns C3 into C3b. Subsequently, FB binds to surface-bound C3b, leading to the formation of the pro-convertase, C3bB. Upon binding to C3b, FB becomes susceptible to proteolytic action by factor D. The enzymatic cleavage by factor D eradicates the pro-peptide fragment Ba (residues 1-234) and engenders the active yet labile convertase, C3bBb. This assemblage comprises C3b and the protease fragment Bb (residues 235-739), thereby inducing an amplification loop within the complement response. This cascade of events culminates in the cleavage of C5 into C5b, perpetuating the progression of the complement response.

Fig.1 Activation of the alternative pathway of complement.

Introduction of Complement Factor B Functional Test

Why get tested?

The complement system has been predominantly perceived as the foremost safeguard against microbial invaders. Nevertheless, a novel outlook has emerged, an array of investigations has illuminated the complicity of complement in the pathogenic orchestration across immune responses, inflammation, neurodegeneration, ischemia, and age-related disorders.

Presently, it is universally acknowledged that the ubiquity and activation of complement hold a pivotal stance in the etiology of an extensive spectrum of diseases. For example, mounting evidence now underscores the participation of FB in ocular angiogenic disorders.

What is being tested?

The assessment of FB formation in conjunction with other influencing factors was conducted through a combination of Surface Plasmon Resonance (SPR) and Enzyme-Linked Immunosorbent Assay (ELISA). Additionally, single-particle electron microscopy and subsequent image processing were employed to scrutinize the structural conformations between FB and the provided samples.

In the course of the analysis, samples furnished by our esteemed clients, exhibiting varying concentration gradients, will undergo rigorous testing. To ensure accuracy and reliability, suitable positive and negative control samples will be meticulously integrated into the experimentation process. Kindly indicate the precise concentration and volume of the samples when dispatching them to our facility.

Which method is commonly used?

Semi-quantitative enzyme-linked immunosorbent assay (ELISA);

Surface plasmon resonance (SPR) technology;

Electron microscopy and three-dimensional reconstruction.

Workflow of Complement Factor B Functional Test

ELISA

Creative Biolabs proposes conducting the complement FB functional assay utilizing the sandwich principle through Enzyme-Linked Immunosorbent Assay (ELISA). This approach offers enhanced convenience and intuitive analysis. Moreover, the incorporation of appropriate positive and negative controls will be ensured.

Fig.2 Workflow of Complement FB ELISA.

SPR

Creative Biolabs advocates the execution of the complement FB functional assay utilizing SPR technology. This method yields outcomes that facilitate the evaluation of activity interactions between FB and test substances, serving as a crucial metric for the assessment of the active ingredient titers in pharmaceutical formulations.

Fig.3 Workflow of complement FB SPR.

Electron microscopy and three-dimensional

Creative Biolabs employs a comprehensive workflow of electron microscopy reconstruction techniques for detailed structural analysis.

Fig.4 Workflow for three-dimensional structural analysis using electron microscopy.

Published Data

Presented are findings showcased within articles pertaining to complement FB functional testing:

1. ELISA & SPR analysis

Fig. 5 ELISA analysis.^{1, 3}.

2. Electron microscopy and 3D reconstruction.

Fig. 6 Factor B structure.^{2, 3}

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Protocols

Why Choose Creative Biolabs?

Creative Biolabs stands poised to be your dependable and credible collaborator, distinguished by:

Resources

Complement Component Factor B/CFB

Complement Activity/Function Assay Products

Complement Testing Services

Creative Biolabs, as a leading R&D service provider, offers a robust complement assay platform supporting complement research, including customized factor B functional tests for enhanced drug discovery in this field. For further details, we invite you to contact with us.

References

1. Couvreur, Bernard, et al. "Variability and action mechanism of a family of anticomplement proteins in Ixodes ricinus." PloS one 3.1 (2008): e1400.
2. Hourcade, Dennis E., and Lynne M. Mitchell. "Access to the complement factor B scissile bond is facilitated by association of factor B with C3b protein." Journal of Biological Chemistry 286.41 (2011): 35725-35732.
3. under Open Access license CC BY 4.0, without modification

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