Sulphide-binding processes of Riftia pachyptila haemoglobins
In: Cahiers de Biologie Marine. Station Biologique de Roscoff: Paris. ISSN 0007-9723; e-ISSN 2262-3094, more Also appears in:(1998). Proceedings of the First International Symposium on Deep-Sea Hydrothermal Vent Biology: Funchal, Madeira, Portugal 20-24 October 1997. Cahiers de Biologie Marine, 39(3-4). Station Biologique de Roscoff: Roscoff. 219-392 pp., more |   |
| Abstract | The deep-sea hydrothermal tube-worm Riftia pachyptila possesses a multi-haemoglobin system with three different extracellular haemoglobins (V1, V2 and C1 Hbs). Unusually, these Hbs can bind oxygen and sulphide at two different sites, simultaneously and reversibly. Two globin chains common to these three Riftia Hbs possess one free cysteine residue and at least one of them is conserved among Vestimentifera and Pogonophora. By selectively blocking the free Cys and using electrospray ionization mass spectrometry experiments, we showed that these Cys are involved in sulphide-binding by Riftia Hbs (Zal et al., 1998). Moreover, we also demonstrated that the larger V1 Hb can form persulphide groups on its linker chains, a mechanism which could account for the higher sulphide-binding potential of this Hb (Zal et al., 1998). |
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