Signal transmission between subunits in the hemoglobin T-state.
J Mol Biol
; 284(5): 1707-16, 1998 Dec 18.
Article
em En
| MEDLINE
| ID: mdl-9878381
To study allosteric mechanism in hemoglobin, a hydrogen-exchange method was used to measure ligand-dependent changes in structural free energy at defined allosterically sensitive positions. When the two alpha-subunits are CN-met liganded, effects can be measured locally, within the alpha-subunit, and also remotely, within the beta-subunit, even though the quaternary structure remains in the T conformation. When the two beta-subunits are liganded, effects occur at the same positions. The effects seen are the same, independently of whether ligands occupy the alpha-chain hemes or the beta-chain hemes. Control experiments rule out modes of energy transfer other than programmed cross-subunit interaction within the T-state. Cross-subunit transfer may depend on pulling the heme trigger (moving the heme iron into the heme plane) rather than on liganding alone.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Hemoglobinas
/
Transdução de Sinais
Limite:
Humans
Idioma:
En
Revista:
J Mol Biol
Ano de publicação:
1998
Tipo de documento:
Article
País de afiliação:
Estados Unidos
País de publicação:
Holanda