16 Extracellular Hemoglobins from Annelids, and their Potential Use in Biotechnology

This chapter highlights the diversity of invertebrate hemoglobin structures, and gathers together up of 100 years of research data. Among invertebrates, annelid hemoglobin structures have been the most widely studied, probably due to their typical symmetric shapes and sizes that allow direct observations to be made using transmission electron microscopy. Hemoglobin seems to be present in all phyla, which suggests a very ancient origin. Using the hemoglobin of the marine annelid Arenicola marina ,t he French biotechnology startup HEMARINA is developing medical products. The first generations of blood substitutes (hemoglobin oxygen carriers) were manufactured using intracellular hemoglobin (human and bovine) in order to function outside the red blood cells. However, HEMARINA technologies are based on a natural extracellular hemoglobin. This circulatory pigment, which is present in the blood vessels of A. marina, has evolved over a million years and is able to function extracellularly. Currently, two main products are under development at HEMARINA, namely HEMO2life 1 (for organ preservation) and HEMOXYCarrier 1 (as a universal oxygen carrier).