Related Experiment Video
Updated: Jun 11, 2026

A Rapid and Chemical-free Hemoglobin Assay with Photothermal Angular Light Scattering
Published on: December 7, 2016
Unveiling the timescale of the R-T transition in human hemoglobin
M Cammarata1, M Levantino, M Wulff
1European Synchrotron Radiation Facility, Grenoble, France.
Abstract:
Time-resolved wide-angle X-ray scattering, a recently developed technique allowing to probe global structural changes of proteins in solution, was used to investigate the kinetics of R-T quaternary transition in human hemoglobin and to systematically compare it to that obtained with time-resolved optical spectroscopy under nearly identical experimental conditions. Our data reveal that the main structural rearrangement associated with the R-T transition takes place approximately 2 mus after the photolysis of hemoglobin at room temperature and neutral pH. This finding suggests that the 20-mus step observed with time-resolved optical spectroscopy corresponds to a small and localized structural change.
Related Concept Videos
Oxygen Transport in the Blood
Hemoglobin
When all four heme groups are bound to oxygen, the resulting molecule is called oxyhemoglobin. As a result, arterial blood...
Gene Families
Occasionally these regions can be adapted to take on new roles within the organism, becoming novel genes...
Lifecycle of Erythrocytes
The resident phagocytic macrophages deal with these damaged cells by engulfing them and separating their globin and heme groups.
Protein and Protein Structure
A protein's shape is critical to its function. For example, an enzyme can...
Cooperative Allosteric Transitions
