TY - JOUR
T1 - Multi-speed sedimentation velocity simulations with UltraScan-III
AU - Williams, Tayler L.
AU - Gorbet, Gary E.
AU - Demeler, Borries
N1 - Publisher Copyright:
© 2018, European Biophysical Societies' Association.
PY - 2018/10/1
Y1 - 2018/10/1
N2 - Recent developments in the UltraScan-III software make it possible to model multi-speed analytical ultracentrifugation sedimentation velocity experiments using finite-element solutions of the Lamm equation. Using simulated data, we demonstrate here how these innovations can be used to enhance the resolution of sedimentation velocity experiments when compared to single-speed experiments. Using heterogeneous systems covering as much as five orders of magnitude in molar mass and fivefold in anisotropy, we compare results from runs performed at multiple speeds to those obtained from single-speed experiments, fitted individually and analyzed globally over multiple speeds, and quantify resolution for sample heterogeneous in size and anisotropy. We also provide guidance on the design of multi-speed experiments and offer a program that can be used to deduce optimal spacing of rotor speeds and speed step durations when a few parameters from the experiment can be estimated. These include the meniscus position, the sedimentation coefficient of the largest species in a mixture, and a solute distribution. Our results show that errors observed in the determination of hydrodynamic parameters for system with great heterogeneity are markedly reduced when multi-speed analysis is employed.
AB - Recent developments in the UltraScan-III software make it possible to model multi-speed analytical ultracentrifugation sedimentation velocity experiments using finite-element solutions of the Lamm equation. Using simulated data, we demonstrate here how these innovations can be used to enhance the resolution of sedimentation velocity experiments when compared to single-speed experiments. Using heterogeneous systems covering as much as five orders of magnitude in molar mass and fivefold in anisotropy, we compare results from runs performed at multiple speeds to those obtained from single-speed experiments, fitted individually and analyzed globally over multiple speeds, and quantify resolution for sample heterogeneous in size and anisotropy. We also provide guidance on the design of multi-speed experiments and offer a program that can be used to deduce optimal spacing of rotor speeds and speed step durations when a few parameters from the experiment can be estimated. These include the meniscus position, the sedimentation coefficient of the largest species in a mixture, and a solute distribution. Our results show that errors observed in the determination of hydrodynamic parameters for system with great heterogeneity are markedly reduced when multi-speed analysis is employed.
KW - Analytical ultracentrifugation
KW - Finite element modeling
KW - Multi-speed analysis
UR - http://www.scopus.com/inward/record.url?scp=85046793466&partnerID=8YFLogxK
U2 - 10.1007/s00249-018-1308-0
DO - 10.1007/s00249-018-1308-0
M3 - Article
C2 - 29748855
AN - SCOPUS:85046793466
SN - 0175-7571
VL - 47
SP - 815
EP - 823
JO - European Biophysics Journal
JF - European Biophysics Journal
IS - 7
ER -