c3b การใช้

• First of all, C5 has to bind to C3b fragment.
• C3b binds to antigen-associated Ig and to the microbe surface.
• The pathway is triggered when the C3b protein directly binds a microbe.
• C3b later joins with C4b2a to make C5 convertase ( C4b2a3b complex ).
• C3b has different binding site for C3bINA, ?1H, factor B and properdin.
• Properdin also inhibits the Factor H  mediated cleavage of C3b by Factor I.
• Microbes may activate the complement system directly and complement component C3b bind to microbes.
• It binds to iC3b ( inactive derivative of C3b ), C3dg, or C3d.
• This protein is also a receptor for the complement component 3 fragments C3b and iC3b.
• It binds to serum factor H, destroying C3-convertase and preventing opsonization by C3b.
• Opsonins include Mfge8, Gas6, Protein S, antibodies and complement factors C1q and C3b.
• The complex of C3b ( 2 ) Bb is a protease which cleaves C5 into C5b and C5a.
• This newly bound C3b recruits more B, D and P activity and greatly amplifies the complement activation.
• At the present, the C3B list is informally maintained by consensus of the callers of that program.
• Next, C3b is broken down progressively to first iC3b, then C3c + C3dg, and then finally C3d.
• The capacity to bind C3b is a stable feature of component C5, as C5b also has this binding capacity.
• Binding ?1H to C3b increases C3bINA binding, while factor B binding prevents C3bINA binding and is competitive with ?1H binding.
• The receptor-opsonin complex can also create byproducts like C3b and C4b which are important components of the complement system.
• In the alternative pathway, C3b binds to Factor B . Factor D releases Factor Ba from Factor B bound to C3b.
• In the alternative pathway, C3b binds to Factor B . Factor D releases Factor Ba from Factor B bound to C3b.