Battle of the Hole Punchers

One of the most exciting lines of research in evolution today is how parasites have become so good at making us sick. A case in point appears in the latest issue of Genome Biology (full text of paper here). It appears that parasites have stolen one of our best lines of defense and now use it against us. When bacteria or other pathogens try to invade our bodies, we marshall an awesome system of biochemistry to ward them off. Recently, a group of French and German molecular biologists took a look at a key piece of that system, a molecule studding the surface of our cells called alpha-2-macroglobulin. Parasites penetrate a host cell by releasing enzymes that can punch a hole through the cell wall. But alpha-2-macroglobulin can snag these enzymes before they do damage, tucking them away in a cage where they can be destroyed. You can find the ...