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Siglecs are SUPER important immune receptors that normally antagonise or induce tolerance in the immune system. Normally they recognise different sialic acids (
by hirenj 4y ago
Siglecs are SUPER important immune receptors that normally antagonise or induce tolerance in the immune system. Normally they recognise different sialic acids (e.g., the same ones recognised by hemaglutinin in influenza) and depending on the health of the cells you can induce different responses in your immune cells.
We’ve done a bit of work in our lab on these receptors, trying to figure out what their natural ligands are. Crazy that the carbon nanotubes are also recognised. I’ll need to check my notes, but I think that the loops that are recognising the nanotubes aren’t where the binding normally is for sialic acids, so it’s all very interesting!
Additional thoughts: I wonder if anyone has tried throwing viral particles or protein pathogens on a carbon nanotube to check for binding. The other Siglecs don’t interact, but hey, maybe we’re lucky and all these pathogen related sialic acid binders happen to have the right residues in place! The SRR bacterial adhesins off the top of my head might be candidates.
- cypherpunks01 4y agoExcuse my ignorance, but how are there carbon nanotube recognizing immune receptors? Do the tubes just happen to fit in the receptors because of their size or shape, or is there something about the tubes that trigger the receptors?
- hirenj 4y agoThe receptors have these floppy loops which are great for bending into the right conformation to recognise different things. It turns out that if they have a few aromatic residues they just happen to recognise carbon nanotubes. It’s unlikely this is something that evolved, and much more just some bad luck in recognising this particular shape.
- robbintt 4y agoWouldn't an aromatic loop have a high affinity for anything with some relatively large / low density (amenable to moving around) electron field?
- maxbond 4y agoSomething that tickles me about this idea is that, if you think of proteins recognizing these small molecules as lock-and-key (I know that model is outmoded), this is the equivalent of a self-impressioning attack (like the Bic pen attack on cheap tubular locks).