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Structure of the altitude adapted hemoglobin of guinea pig in the R2-state.

ABSTRACT: Guinea pigs are considered to be genetically adapted to a high altitude environment based on the consistent finding of a high oxygen affinity of their blood.The crystal structure of guinea pig hemoglobin at 1.8 A resolution suggests that the increased oxygen affinity of guinea pig hemoglobin can be explained by two factors, namely a decreased stability of the T-state and an increased stability of the R2-state. The destabilization of the T-state can be related to the substitution of a highly conserved proline (P44) to histidine (H44) in the alpha-subunit, which causes a steric hindrance with H97 of the beta-subunit in the switch region. The stabilization of the R2-state is caused by two additional salt bridges at the beta1/beta2 interface.Both factors together are supposed to serve to shift the equilibrium between the conformational states towards the high affinity relaxed states resulting in an increased oxygen affinity.

SUBMITTER: Pairet B

PROVIDER: S-EPMC2927554 | biostudies-literature | 2010 Aug

REPOSITORIES: biostudies-literature

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Structure of the altitude adapted hemoglobin of guinea pig in the R2-state.

Pairet Bruno B Jaenicke Elmar E

PloS one 20100824 8

<h4>Background</h4>Guinea pigs are considered to be genetically adapted to a high altitude environment based on the consistent finding of a high oxygen affinity of their blood.<h4>Methodology/principal findings</h4>The crystal structure of guinea pig hemoglobin at 1.8 A resolution suggests that the increased oxygen affinity of guinea pig hemoglobin can be explained by two factors, namely a decreased stability of the T-state and an increased stability of the R2-state. The destabilization of the T ...[more]

PMID: 20811494

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Structure of the altitude adapted hemoglobin of guinea pig in the R2-state.

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Structure of the altitude adapted hemoglobin of guinea pig in the R2-state.

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