Antibodies have two identical arms (known as Fab regions) to increase their binding efficacy and versatility in neutralizing pathogens. Here’s why: 1. **Increased Binding Strength**: The two arms can simultaneously bind to two identical or similar antigenic sites on the same pathogen. This bivalent binding increases the overall strength of the interaction, making it harder for the pathogen to dissociate from the antibody. 2. **Cross-Linking**: The two arms can bind to different pathogens simultaneously, which helps aggregate pathogens together. This cross-linking can facilitate pathogen removal by immune cells and prevent the spread of infection. 3. **Redundancy and Flexibility**: If one arm encounters an antigen that it cannot bind to effectively due to a mutation or a slight difference in the antigen, the other arm may still succeed in binding. This redundancy enhances the antibody's ability to function in a variable environment. 4. **Activation of Effector Functions**: Binding of both arms to antigens can help activate other parts of the immune system, such as complement fixation or Fc receptor engagement, more efficiently.
@@WillThomson-st6hm Both the light chains and the heavy chains are produced by a random process to ensure that a huge range are made. But this process results in identical pairs being created. So are both arms produced?
@@christopherrobinson7541 im not sure. I just found briannes channel and was surveying how few comments there are. I was looking for anyone actually doing science/asking science questions. Yours was about the only one I found. So I got the gpt to answer your question. I'm curious too, why two identical arms. The gpt gave some good answers, but it said if one arm doesn't bind the other might, I don't see how if they are both identical, I'm mixed science and engineering, so what I imagine is it has to do with angle of binding, the antibody has a wider angle, if it's got two arms spread out like that. And harder to dislodge. Viruses have wave glycan sugars that act like windscreen wipers trying to push antibodies away. It might help stabilise the antibody from being knocked sideways and dislodging.
