Common Terminator Pathway

Question 1

What do all 3 initiator pathways produce?

Answer 1

C5b

Question 2

What does C5b bind to?

Answer 2

C6

Question 3

What does C5b6 bind?

What does the binding induce?

Answer 3

C7

Induces a conformational change revealing a hydrophobic domain in C7 which inserts into the target cell membrane

Question 4

If the C5b,6,7 complex is properly inserted into a membrane what happens?

Answer 4

The membrane will bind C8 and lots of C9 molecules start to form a ring

Question 5

What does C9 do?

Answer 5

They polymerize side-by-side to form a “pore” in the target cell membrane - MAC membrane attack complex

Question 6

In addition to MAC, complement is able to mediate other effector functions such as (2)

Answer 6

1. Opsonize - C3a, and C5a drive inflammation and recruit phagocytic cells
2. Cellular activation: Phagocytes have receptors for C3b to engulf and destroy the pathogen
3. Inflammation