Haemocyanin
copper-containing proteins that transport oxygen in some invertebrates
Haemocyanin (or hemocyanin) is a protein which transports oxygen in the bodies of some invertebrates. Their active centre has two copper atoms which reversibly bind a single oxygen molecule (O2). Unlike the hemoglobin in red blood cells found in vertebrates, hemocyanins are not bound to blood cells. The molecules are carried in the haemolymph.
![](http://up.wiki.x.io/wikipedia/commons/thumb/f/fb/Hemocyanin2.jpg/250px-Hemocyanin2.jpg)
![](http://up.wiki.x.io/wikipedia/commons/thumb/a/a0/Hemocyanin_Example.jpg/220px-Hemocyanin_Example.jpg)
Hemocyanins are found only in the Mollusca and Arthropoda.[1][2] However, the molecule is used only in a few insects. This is because insects evolved another system: the direct transfer of oxygen to tissues by a system of tubes called trachea. This delivers oxygen direct to the wing muscles and other organs.
References
change- ↑ Burmester T. 2001. Molecular evolution of the arthropod hemocyanin superfamily. Mol. Biol. Evol. 18 (2): 184–195.
- ↑ Voit R. et al 2000. Complete sequence of the 24-mer hemocyanin of the tarantula Eurypelma californicum. Structure and intramolecular evolution of the subunits. J. Biol. Chem. 275 (50): 39339–44. [1]