Direct Observation of Insulin Association Dynamics with Time-Resolved X-ray Scattering
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
- Center for Advanced Radiation Sources, The University of Chicago, Chicago, Illinois 60637, United States
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States; Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
Biological functions frequently require protein-protein interactions that involve secondary and tertiary structural perturbation. Here we study protein-protein dissociation and reassociation dynamics in insulin, a model system for protein oligomerization. Insulin dimer dissociation into monomers was induced by a nanosecond temperature-jump (T-jump) of ~8 °C in aqueous solution, and the resulting protein and solvent dynamics were tracked by time-resolved X-ray solution scattering (TRXSS) on time scales of 10 ns to 100 ms. The protein scattering signals revealed the formation of five distinguishable transient species during the association process that deviate from simple two state kinetics. Our results show that the combination of T-jump pump coupled to TRXSS probe allows for direct tracking of structural dynamics in nonphotoactive proteins.
- Research Organization:
- Argonne National Laboratory (ANL)
- Sponsoring Organization:
- National Institutes of Health (NIH)
- DOE Contract Number:
- AC02-06CH11357
- OSTI ID:
- 1406920
- Journal Information:
- Journal of Physical Chemistry Letters, Journal Name: Journal of Physical Chemistry Letters Journal Issue: 18 Vol. 8; ISSN 1948-7185
- Publisher:
- American Chemical Society
- Country of Publication:
- United States
- Language:
- English
Similar Records
Insulin hexamer dissociation dynamics revealed by photoinduced T -jumps and time-resolved X-ray solution scattering
Human platelet factor 4 subunit association/dissociation thermodynamics and kinetics