Hemoglobins from deep-sea hydrothermal vent scaleworms of the genusBranchipolynoe: A new type of quaternary structure

Autor: Stéphane Hourdez, André Toulmond, François H. Lallier, Brian N. Green
Rok vydání: 1999
Předmět:
Zdroj: Proteins: Structure, Function, and Genetics. 34:427-434
ISSN: 1097-0134
0887-3585
DOI: 10.1002/(sici)1097-0134(19990301)34:4<427::aid-prot2>3.0.co;2-l
Popis: Branchipolynoe symmytilida and B. seepensis are two scaleworms (Polychaeta; Polynoidae) living commensally in the mantle cavity of deep-sea hydrothermal vent and cold-seep mussels. In contrast with littoral members of this family, the two species exhibit a large amount of extracellular hemoglobin (Hb) in their coelomic fluid. Gel filtration revealed the existence of four different Hbs: one minor, high molecular mass (3x10(6) Da) Hb, V1-Hb, reminiscent of a vascular hexagonal bilayer annelid Hb; two major coelomic Hbs, C1-Hb, and C2-Hb, with unusual masses for extracellular annelid Hbs of 153 and 124 kDa respectively; and a minor probably coelomic Hb of 23 kDa (C3-Hb). Using electrospray ionization mass spectrometry, SDS-PAGE after subtilisin treatment, and tandem mass spectrometry, we showed that C1-Hb is a trimer of a 57,996 Da chain and C2-Hb is a dimer of a 57,648 Da chain, each chain being a four-domain/four-heme polypeptide. This multimeric, multidomain arrangement is unique among annelid Hbs and appears different from that of other known multidomain Hbs.
Databáze: OpenAIRE
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