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