Related Experiment Video
Updated: Jun 13, 2026

T-wave Ion Mobility-mass Spectrometry: Basic Experimental Procedures for Protein Complex Analysis
Published on: July 31, 2010
Spontaneous quaternary and tertiary T-R transitions of human hemoglobin in molecular dynamics simulation
Jochen S Hub1, Marcus B Kubitzki, Bert L de Groot
1Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden.
Abstract:
We present molecular dynamics simulations of unliganded human hemoglobin (Hb) A under physiological conditions, starting from the R, R2, and T state. The simulations were carried out with protonated and deprotonated HC3 histidines His(beta)146, and they sum up to a total length of 5.6 micros. We observe spontaneous and reproducible T-->R quaternary transitions of the Hb tetramer and tertiary transitions of the alpha and beta subunits, as detected from principal component projections, from an RMSD measure, and from rigid body rotation analysis. The simulations reveal a marked asymmetry between the alpha and beta subunits. Using the mutual information as correlation measure, we find that the beta subunits are substantially more strongly linked to the quaternary transition than the alpha subunits. In addition, the tertiary populations of the alpha and beta subunits differ substantially, with the beta subunits showing a tendency towards R, and the alpha subunits showing a tendency towards T. Based on the simulation results, we present a transition pathway for coupled quaternary and tertiary transitions between the R and T conformations of Hb.
Related Concept Videos
Gene Families
Occasionally these regions can be adapted to take on new roles within the organism, becoming novel genes...
Globular and Fibrous Proteins
Globular proteins are also known as spheroproteins and typically are approximately round in shape. They contain a mix of amino acid types and contain differing sequences in their primary structures. Globular proteins have many different functions, such as enzymes, cellular messengers, and molecular transporters. These roles often require the proteins to be...
Protein and Protein Structure
A protein's shape is critical to its function. For example, an enzyme can...
Cooperative Allosteric Transitions
Cooperative Allosteric Transitions
Cooperative Allosteric Transitions

