Allosteric transition intermediates modelled by crosslinked haemoglobins.

Published

Journal Article

The structural end-points of haemoglobin's transition from its low-oxygen-affinity (T) to high-oxygen-affinity (R) state, have been well established by X-ray crystallography, but short-lived intermediates have proved less amenable to X-ray studies. Here we use chemical crosslinking to fix these intermediates for structural characterization. We describe the X-ray structures of three haemoglobins, alpha 2 beta 1S82 beta, alpha 2 beta 1Tm82 beta and alpha 2 beta 1,82Tm82 beta, which were crosslinked between the amino groups of residues beta Val1 and beta Lys82 by 3,3'-stilbenedicarboxylic acid (S) or trimesic acid (Tm) while in the deoxy state, and saturated with carbon monoxide before crystallization. alpha 2 beta 1S82 beta, which has almost normal oxygen affinity, is completely in the R-state conformation; however, alpha 2 beta 1Tm82 beta and alpha 2 beta 1,82Tm82 beta, both of which have low oxygen affinity, have been prevented from completing their transition into the R state and display many features of a transitional intermediate. These haemoglobins therefore represent a snapshot of the nascent R state.

Full Text

Duke Authors

Cited Authors

  • Schumacher, MA; Dixon, MM; Kluger, R; Jones, RT; Brennan, RG

Published Date

  • May 4, 1995

Published In

Volume / Issue

  • 375 / 6526

Start / End Page

  • 84 - 87

PubMed ID

  • 7723849

Pubmed Central ID

  • 7723849

International Standard Serial Number (ISSN)

  • 0028-0836

Digital Object Identifier (DOI)

  • 10.1038/375084a0

Language

  • eng

Conference Location

  • England