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T-wave Ion Mobility-mass Spectrometry: Basic Experimental Procedures for Protein Complex Analysis
Published on: July 31, 2010
Conformation-invariant structures of the alpha1beta1 human hemoglobin dimer
W L Nichols1, B H Zimm, L F Ten Eyck
1Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093-0654, USA.
Journal of Molecular Biology
|July 25, 1997
Summary
Researchers analyzed human hemoglobin structure changes between oxygenated and deoxygenated states. They identified rigid domains and tertiary substructures, revealing how heme pockets communicate changes to the dimer core, explaining cooperativity.
Area of Science:
- Biophysics
- Structural Biology
- Molecular Dynamics
Background:
- Conformational changes in hemoglobin between oxy and deoxy states are complex.
- Correlated motions and shifting coordinate systems complicate structural analysis.
Purpose of the Study:
- To analyze structural differences between oxy and deoxy human hemoglobin alphabeta dimer.
- To identify invariant substructures independent of reference frames.
Main Methods:
- Employed frame-independent methods to analyze hemoglobin structure.
- Decomposed the hemoglobin dimer into rigid domains and tertiary substructures.
Main Results:
- Identified 15 persistent substructures, including rigid domains and tertiary substructures.
- Characterized a large rigid core (44% of dimer) and heme pocket domains.
- Described the dimer as a framework of stiff elements, with heme pockets connected to the core by CD and FG corners.
Conclusions:
- Hemoglobin structure can be viewed as rearrangements of rigid and tertiary substructures.
- FG corners mediate communication between heme pockets and the dimer core, potentially explaining heme-heme cooperativity.
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