The extracellular haemoglobins of Artemia sp.: a biochemical and ontogenetical study
Moens, L. (1982). The extracellular haemoglobins of Artemia sp.: a biochemical and ontogenetical study. Meded. Kon. Acad. Wet. Lett. Kunst. Klasse der Wet. Academiae Analecta, 44(1): 1-21
In: Mededelingen van de Koninklijke Academie voor Wetenschappen, Letteren en Schone Kunsten van België. Klasse der Wetenschappen. Paleis der Academiën: Brussel. ISSN 0369-285x, more
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| Keywords |
Organic compounds > Carbohydrates > Glycosides > Pigments > Respiratory pigments > Haemoglobins
Artemia Leach, 1819 [WoRMS]
Marine/Coastal |
| Abstract |
The haemolymph of the Crustaceae Artemia sp. contains three extracellular Hb's. The Hb phenotype is, besides genetic factors, determined by ontogenetic development and by the oxygen concentration in the environment. The three Hb's exhibit different oxygen binding characteristics. They are adapted in such a way that by varying the relative proportions of their Hb's the animals become able to cope with extremely different environmental conditions of pH, salinity, temperature, and oxygen concentration. The isolated Hb's were structurally characterized. The native molecules are dimers of two different multihaem containing globin chains of 122,000 dalton. Hb I and Hb III are homodimers respectively of the alpha(alpha2) and bèta(bèta2) chain and Hb II is a alpha-bèta heterodimer. Enzymatic cleavage of these globin chains yields haem containing polypeptides or domains of 16-17,000 dalton corresponding to an oxygen binding unit. This suggests that the Artemia globin chains, like other invertebrate globins, are composed of a series of almost identical domains. The similarity of these domains with the vertebrate globins and myoglobins puts forward the question of their evolutionary relationship. |
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