Asked by: Isidora Saragueta
medical health vaccines

Which complement protein is used as an Opsonin?

Last Updated: 3rd June, 2020

C3b, C4b, and C1q are important complement molecules that serve as opsonins. As a part of the alternative complement pathway, the spontaneous activation of a complement cascade converts C3 to C3b, a component that can serve as an opsonin when bound to an antigen's surface.

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Furthermore, what are examples of Opsonins?

Examples of opsonins include IgG antibody - part of the immune response - and the C3b molecule of the complement system. Each has receptors for both foreign particle and host phagocyte.

Additionally, where are the complement proteins found in the body? Complement is an assembly of proteins found in the blood and body fluids and on cell surfaces.

Keeping this in consideration, is c3a an Opsonin?

C3b remains bound to the complex at the surface of the microorganism. This not only activates the next step, but also C3b is a good opsonin. The small peptide, C3a diffuses away and acts as a chemotactic factor and an inflammatory paracrine.

Which antibodies are Opsonins?

1. Opsonization, or enhanced attachment, refers to the antibody molecules IgG and IgE, the complement proteins C3b and C4b, and other opsonins attaching antigens to phagocytes. 2. The Fab portions of the antibody IgG react with epitopes of the antigen.

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