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The hemoglobin system of the brown moray Gymnothorax unicolor: structure/function relationships

The hemoglobin system of the brown moray Gymnothorax unicolor: structure/function relationships

Authors :
Cinzia Verde
Bruno Giardina
Mariagiuseppina Pellegrini
Guido di Prisco
Maria Teresa Sanna
Alessandra Olianas
Anna Maria Deiana
Antonella Fais
Marcella Corda
Maurizio Tamburrini
Source :
268 (2001): 4104–4111., info:cnr-pdr/source/autori:Tamburrini M.1, Verde C.1, Olianas A.2, Giardina B.3, Corda M.2, Sanna M.T.2, Fais A.2, Deiana A.M.2, di Prisco G.1, Pellegrini M.2/titolo:The hemoglobin system of the brown moray Gymnothorax unicolor. Structure%2Ffunction relationships./doi:/rivista:/anno:2001/pagina_da:4104/pagina_a:4111/intervallo_pagine:4104–4111/volume:268
Publication Year :
2001

Abstract

The Gymnothorax unicolor hemoglobin system is characterized by two components, called cathodic and anodic on the basis of their isoelectric point, which were separated by ion-exchange chromatography. The oxygen-binding properties of the purified components were studied in the absence and presence of chloride and/or GTP or ATP in the pH range 6.5-8.0. Stripped cathodic hemoglobin showed a small reverse Bohr effect, high oxygen affinity, and low co-operativity; the addition of chloride only caused a small decrease in oxygen affinity. In the presence of GTP or ATP, the oxygen affinity was dramatically reduced, the co-operativity increased, and the reverse Bohr effect abolished. Stripped anodic hemoglobin is characterized by both low oxygen affinity and co-operativity, and displayed a normal Bohr effect; the addition of chloride increased co-operativity, whereas ATP and GTP significantly modulated oxygen affinity at acidic pH values, enhancing the Bohr effect and giving rise to the Root effect. The complete amino-acid sequences of the alpha and beta chains of both hemoglobins were established; the molecular basis of the functional properties of the hemoglobins is discussed in the light of the primary structure and compared with those of other fish hemoglobins.

Details

ISSN :
00142956
Volume :
268
Issue :
14
Database :
OpenAIRE
Journal :
European journal of biochemistry
Accession number :
edsair.doi.dedup.....26c57f513f99b0b452578e045b553970