Complement Membrane Attack Complex
The membrane attack complex (MAC) is typically formed on the surface of pathogenic bacterial cells as a result of the activation of the alternative pathway and the classical pathway of the complement system, and it is one of the effector proteins of the immune system. The membrane-attack complex (MAC) forms transmembrane channels. These channels disrupt the phospholipid bilayer of target cells, leading to cell lysis and death.
A number of proteins participate in the assembly of the MAC. Freshly activated C5b binds to C6 to form a C5b-6 complex, then to C7 forming the C5b-7 complex. The C5b-7 complex binds to C8, which is composed of three chains (alpha, beta, and gamma), thus forming the C5b-8 complex. C5b-8 subsequently binds to C9 and acts as a catalyst in the polymerization of C9. Active MAC has a subunit composition of C5b-C6-C7-C8-C9{n}.
Read more about Complement Membrane Attack Complex: Structure and Function, Initiation: C5-C7, Polymerization: C8-C9, Inhibition
Famous quotes containing the words complement, attack and/or complex:
“A healthy man, indeed, is the complement of the seasons, and in winter, summer is in his heart.”
—Henry David Thoreau (1817–1862)
“...I believed passionately that Communists were a race of horned men who divided their time equally between the burning of Nancy Drew books and the devising of a plan of nuclear attack that would land the largest and most lethal bomb squarely upon the third-grade class of Thomas Jefferson School in Morristown, New Jersey.”
—Fran Lebowitz (b. 1950)
“In the case of all other sciences, arts, skills, and crafts, everyone is convinced that a complex and laborious programme of learning and practice is necessary for competence. Yet when it comes to philosophy, there seems to be a currently prevailing prejudice to the effect that, although not everyone who has eyes and fingers, and is given leather and last, is at once in a position to make shoes, everyone nevertheless immediately understands how to philosophize.”
—Georg Wilhelm Friedrich Hegel (1770–1831)