Membrane Attack Complex / MAC: Complement Component C8

Membrane Attack Complex / MAC: Complement Component C8

Complement Receptor Structure (Proteins | Antibodies | Genes | ELISA Kits)

Complement Component / Protein Structure (Proteins | Antibodies | Genes | ELISA Kits)

Membrane Attack Complex / MAC: Complement Component C8 Background

Complement component C8 plays a pivotal role in the formation of the membrane attack complex (MAC), an important antibacterial immune effector. C8 initiates membrane penetration and coordinates MAC pore formation. MAC is generated by sequential addition of C5b, C6, C7, C8, and C9 molecules, which results in the transmembrane pore and eventual cell lysis. After binding to C8,C5b-7 complex, by itself transiently bound to membrane surface and nonfunctional, is endowed with the ability to cause membrane damage and polymerization of C9 that greatly accelerate MAC activity.

Membrane Attack Complex / MAC: Complement Component C8 Deficiency

Complement component 8 deficiency is a disorder that causes the immune system to malfunction, resulting in a form of immunodeficiency. Immunodeficiencies are conditions in which the immune system is not able to protect the body effectively from foreign invaders such as bacteria. People with complement component 8 deficiency have a significantly increased risk of recurrent bacterial infections, particularly by a bacterium called Neisseria meningitidis. Although meningitis can be life-threatening, individuals with complement component 8 deficiency are less likely to die from the infection than people in the general population who contract it.

There are two types of complement component 8 deficiency, types I and II, classified by their genetic cause. The two types have the same signs and symptoms. In addition, Complement component 8 deficiency is a rare disorder, although its prevalence is unknown. Type I occurs in several populations, particularly in people with Hispanic, Japanese, or African Caribbean heritage, whereas type II primarily occurs in people of Northern European descent.

Membrane Attack Complex / MAC: Complement Component C8 References

1. Bubeck D, et al. (2011). Structure of human complement C8, a precursor to membrane attack. Journal of molecular biology, 405(2), 325-330.
2. Kojima T, et al. (1998). Genetic basis of human complement C8α-γ deficiency. The Journal of Immunology, 161(7), 3762-3766.

Complement System
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Complement System Component / Protein Regulator and Receptor
Complement Genetic Feature
Complement Activation Pathways
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Complement System and Diseases
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Complement System Structure
Complement Membrane Attack Complex/MAC+
- Membrane Attack Complex / MAC: Complement Component C5
- Membrane Attack Complex / MAC: Complement Component C6
- Membrane Attack Complex / MAC: Complement Component C7
- Membrane Attack Complex / MAC: Complement Component C8
- Membrane Attack Complex / MAC: Complement Component C9
Complement Component / Protein Structure
Complement Regulator Structure
Complement Receptor Structure
Collectins and Ficolins: Humoral Lectins of the Innate Immune System
Complement System Effector Functions
Anti-Complement Antibody Products