Jump to content

Complement system


Recommended Posts

Hi!

We are a study group on our second year of medical laboratory science, and our immunology exam is coming up. There is some confusion though.

 

When C1q binds the antibody, C1r is activated and then cleaved and activates C1s. Then C1s will cleave C4 and C2. C4b and C2a will then bind to the pathogen and the antibody, and then C4b2a is formed. Now, the question is:

 

Is C3b2a a C3-convertase or a C3/C5-convertase? Our textbook says C3/C5-convertase, but I've been studying a bit on the Internet as well, and there I've read that it's a C3-convertase. What is correct? Doesn't C3b2a turn into C3/C5-convertase when it binds another C3b and becomes C3b2a3b-complex? Our textbook says nothing about C3b binding to C3b2a, just that C3b2a is C3/C5-convertase.

 

I hope this makes sense, thanks for any help! :)

Link to comment
Share on other sites

  • 3 weeks later...

Are you talking about C4b2a or C3b2a? C4b2a and C3bBb are both C3 convertases - C3 convertase is the point at which both the classic and alternative cascades converge. Once C4b2a cleaves C3, C4b2a3b is the C5 convertase, while C3a is a pyrogen.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.