Fish hemoglobins
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Data
2007-06-01
Autores
Souza, P. C. de [UNESP]
Bonilla-Rodriguez, Gustavo Orlando [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Associação Brasileira de Divulgação Científica (ABRADIC)
Resumo
Vertebrate hemoglobin, contained in erythrocytes, is a globular protein with a quaternary structure composed of 4 globin chains (2 alpha and 2 beta) and a prosthetic group named heme bound to each one. Having myoglobin as an ancestor, hemoglobin acquired the capacity to respond to chemical stimuli that modulate its function according to tissue requirements for oxygen. Fish are generally submitted to spatial and temporal O2 variations and have developed anatomical, physiological and biochemical strategies to adapt to the changing environmental gas availability. Structurally, most fish hemoglobins are tetrameric; however, those from some species such as lamprey and hagfish dissociate, being monomeric when oxygenated and oligomeric when deoxygenated. Fish blood frequently possesses several hemoglobins; the primary origin of this finding lies in the polymorphism that occurs in the globin loci, an aspect that may occasionally confer advantages to its carriers or even be a harmless evolutionary remnant. on the other hand, the functional properties exhibit different behaviors, ranging from a total absence of responses to allosteric regulation to drastic ones, such as the Root effect.
Descrição
Palavras-chave
Hemoglobin S, Fish, Root effect, Bohr effect
Como citar
Brazilian Journal of Medical and Biological Research. Associação Brasileira de Divulgação Científica, v. 40, n. 6, p. 769-778, 2007.