Quantitative Analysis of Protein Self‐Association by Sedimentation Velocity

Sedimentation velocity analytical ultracentrifugation is a powerful classical method to study protein self‐association processes in solution based on the size‐dependent macromolecular migration in the centrifugal field. This technique can elucidate the assembly scheme, measure affinities ranging from picomolar to millimolar Kd, and in favorable cases provide information on oligomer lifetimes and hydrodynamic shape. The present step‐by‐step protocols detail the essential steps of instrument calibration, experimental setup, and data analysis. Using a widely available commercial protein as a model system, the protocols invite replication and comparison with our results. A commentary discusses principles for modifications in the protocols that may be necessary to optimize application of sedimentation velocity analysis to other self‐associating proteins.