Small angle X-ray scattering from biological macromolecules in - - PowerPoint PPT Presentation
Small angle X-ray scattering from biological macromolecules in solution Al Kikhney European Molecular Biology Laboratory Austria Belgium Croatia Denmark Finland France Hamburg/DESY Germany EBI/Hinxton Greece Iceland
Small angle X-ray scattering
from biological macromolecules in solution
Al Kikhney
Hamburg/DESY
Austria Belgium Croatia Denmark Finland France Germany Greece Iceland Ireland Israel Italy Luxembourg Netherlands Norway Portugal Spain Sweden Switzerland United Kingdom + Australia
Melbourne ↓
Meyer-Klaucke team
DESY, Hamburg, Germany
EMBL
Macromolecular crystallography Small angle X-ray scattering
Since 1974
2 MX beamlines 1 BioSAXS beamline
DORIS III Biological SAXS at EMBL
Group leader: Dmitri Svergun Staff: M. Petoukhov, C. Blanchet, D. Franke, A. Kikhney Staff with joint appointments: P. Konarev Postdocs: M. Gräwert, C. Jeffries, G. Schenk, A. Spilotros, A. Tuukkanen PhD students: G. Tria, M. Kachala, E. Valentini Trainees: M. Franklin, D. Ruskule
Major Tasks Running EMBL SAXS beamline P12 at Petra-III User support and collaborative projects Development of data analysis methods Education and training (including regular courses)
Biological SAXS at EMBL
solution
Small Angle X-ray Scattering
|s| = 4π sinθ/λ s – scattering vector 2θ – scattering angle λ – wavelength I(s) – intensity
X-rays →
X-ray detector
2θ s
Homogeneous and monodisperse solution
solvent
1-2 mg purified material concentration from 0.5 mg/ml, exposure times: a few seconds/minutes
Small Angle X-ray Scattering
Exposure
X-ray detector beamstop
Small Angle X-ray Scattering
Exposure
beamstop
Small Angle X-ray Scattering
Exposure
Log I(s) a.u. s, nm-1
Shape and size
lysozyme apoferritin
Log I(s) a.u. s, nm-1
SAXS studies of biological macromolecules
Rg MM Volume
Shape Rigid body modelling Missing fragments Flexible systems Oligomeric mixtures
SAXS studies of biological macromolecules
Rg MM Volume
Shape Rigid body modelling Missing fragments Flexible systems Oligomeric mixtures
software package
www.embl-hamburg.de/biosaxs/software.html
Crystal solution solution
vs.
Crystal solution solution
vs.
Crystal solution
vs.
Crystal solution
vs. No need to grow crystals No crystallographic packing forces are present Not limited by molecular mass Applicable under nearly any physiological conditions Observe responses to changes in conditions Quantitative analysis of complex systems and processes
SAXS
Problems
Outline