An Important Protein in the Activation of the Alternative Pathway

Question

An important protein in the activation of the alternative pathway of complement activation is
A) properdin.
B) interferon.
C) histamine.
D) fibrin.
E) C1.

Accepted Answer

The alternative pathway of complement activation is activated by the presence of foreign material, such as bacterial or viral surfaces. Properdin, also known as factor P, is a protein that stabilizes the C3 and C5 convertases of the alternative pathway, leading to the amplification of complement activation and the subsequent destruction of the invading pathogen.