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New insights into the proton-dependent oxygen affinity of Root effect haemoglobins.

Publication ,  Journal Article
Bonaventura, C; Crumbliss, AL; Weber, RE
Published in: Acta physiologica Scandinavica
November 2004

A long-standing puzzle with regard to protein structure/function relationships is the proton-dependent modification of haemoglobin (Hb) structure that causes oxygen to be unloaded from Root effect Hbs into the swim bladders and eyes of fish even against high oxygen pressure gradients. Although oxygen unloading in Root effect Hbs has generally been attributed to proton-dependent stabilization of the T-state, protonation of Root effect Hbs can alter their ligand affinities in both R- and T-state conformations and either stabilize the T-state or destabilize the R-state. The C-terminal residues that are so important in the Bohr effect of human Hb appear to be involved in the Root effects of some fish Hbs and not in others, indicating that several evolutionary pathways have resulted in expression of highly pH-dependent Hbs. New data are presented that show surprising similarities in the pH- and anion-dependence of sulfhydryl group reactivity and anaerobic oxidation of human and fish Hbs. The available evidence supports the concept that in both Bohr effect and Root effect Hbs a large steric component acts in addition to quaternary shifts between R and T conformations to regulate ligand affinity. Allosteric effectors moderate these steric effects within both R- and T-state conformations and allow for an elegant match between Hb function and the wide-ranging physiological needs of diverse organisms.

Duke Scholars

Published In

Acta physiologica Scandinavica

DOI

EISSN

1365-201X

ISSN

0001-6772

Publication Date

November 2004

Volume

182

Issue

3

Start / End Page

245 / 258

Related Subject Headings

  • Tuna
  • Sulfhydryl Compounds
  • Structure-Activity Relationship
  • Protons
  • Protein Conformation
  • Physiology
  • Oxygen
  • Oxidation-Reduction
  • Hydrogen-Ion Concentration
  • Humans
 

Citation

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Bonaventura, C., Crumbliss, A. L., & Weber, R. E. (2004). New insights into the proton-dependent oxygen affinity of Root effect haemoglobins. Acta Physiologica Scandinavica, 182(3), 245–258. https://doi.org/10.1111/j.1365-201x.2004.01359.x
Bonaventura, C., A. L. Crumbliss, and R. E. Weber. “New insights into the proton-dependent oxygen affinity of Root effect haemoglobins.Acta Physiologica Scandinavica 182, no. 3 (November 2004): 245–58. https://doi.org/10.1111/j.1365-201x.2004.01359.x.
Bonaventura C, Crumbliss AL, Weber RE. New insights into the proton-dependent oxygen affinity of Root effect haemoglobins. Acta physiologica Scandinavica. 2004 Nov;182(3):245–58.
Bonaventura, C., et al. “New insights into the proton-dependent oxygen affinity of Root effect haemoglobins.Acta Physiologica Scandinavica, vol. 182, no. 3, Nov. 2004, pp. 245–58. Epmc, doi:10.1111/j.1365-201x.2004.01359.x.
Bonaventura C, Crumbliss AL, Weber RE. New insights into the proton-dependent oxygen affinity of Root effect haemoglobins. Acta physiologica Scandinavica. 2004 Nov;182(3):245–258.

Published In

Acta physiologica Scandinavica

DOI

EISSN

1365-201X

ISSN

0001-6772

Publication Date

November 2004

Volume

182

Issue

3

Start / End Page

245 / 258

Related Subject Headings

  • Tuna
  • Sulfhydryl Compounds
  • Structure-Activity Relationship
  • Protons
  • Protein Conformation
  • Physiology
  • Oxygen
  • Oxidation-Reduction
  • Hydrogen-Ion Concentration
  • Humans