Hemocyanin

• UniProt: P80888

Hemocyanin ( gr of heme, Blood and kyanos, sky blue ') is a hemoglobin of arthropods (among cancers; arachnids, insect, which possess tracheae, to a lesser extent it occurs ) and molluscs ( u a mussels, snails and squid). He serves as an oxygen transporter.

Unlike the red, iron-containing hemoglobin, the oxygen in the hemocyanin of two copper ion is bound. Also does not hemocyanin porphyrin structure as heme, the copper ions are instead attached through amino acid residues ( histidine) to the protein. Oxygen-free hemocyanin is colorless, with bound oxygen, it has a blue color.

The binding of oxygen is higher than in the hemoglobin. However, in comparison with the hemoglobin hemocyanin has a lower oxygen binding capacity which leads to a lower overall capacity for the transportation of oxygen.

And the binding mode of the oxygen is in contrast to the iron-containing compounds and Hemerythrin hemoglobin, in which the oxygen is bonded to a terminal on an iron atom. When hemocyanin oxygen bridging between two copper (I ) atoms is incorporated, which are oxidized to copper (II).

Hemocyanin elicits strong immune responses of the immune systems of mammals. It is therefore used as an adjuvant. However, it is completely non-toxic and is rapidly degraded.