Once a parasite makes it past our outer defences, it encounters some seriously sophisticated weaponry. One of these is the ever-shifting antibody, my seventh structure of Christmas.
Every large organism – you included – is just a feast laid out for any parasite (bacteria, virus or beastie) clever enough to break in and access its carefully amassed energy. Throughout the Billion-Years’ Evolutionary War between hosts and parasites, the host has always been on the defensive, endlessly innovating to fend off invaders.
Continue reading “Antibodies: Defend!”
The second structure of Christmas is the membrane protein opsin, which allows us to perceive light.
Proteins that control the information going in and out of our cells are harder to crystallise than run-of-the-mill globular proteins, as they have both water-loving and fat-loving parts and are tricky to mass produce. Opsin, our second structure of Christmas, is one such molecule. It is situated on a special membrane in a specialised cell at the back of our eyes, and senses light.
Continue reading “Seeing the light: opsin”