Conformational analysis of a genetically encoded FRET biosensor by SAXS.

Mertens HD, Piljić A, Schultz C, Svergun DI, Biophys J 102(12):2866-75 (2012) Europe PMC

SASDAJ5 – Annexin-A4

MWI(0) 33 kDa
MWexpected 36 kDa
VPorod 54 nm3
log I(s) 4.02×101 4.02×100 4.02×10-1 4.02×10-2
Annexin-A4 small angle scattering data  s, nm-1
ln I(s)
Annexin-A4 Guinier plot ln 4.03×101 Rg: 2.4 nm 0 (2.4 nm)-2 s2
Annexin-A4 Kratky plot 1.104 0 3 sRg
Annexin-A4 pair distance distribution function Rg: 2.4 nm 0 Dmax: 7.6 nm

Data validation

Fits and models

log I(s)
 s, nm-1
Annexin-A4 CRYSOL model

log I(s)
 s, nm-1
Annexin-A4 DAMMIF model

Synchrotron SAXS data from solutions of Annexin-A4 in 50 mM HEPES 50 mM KCl, pH 7.5 were collected on the EMBL X33 beam line at the DORIS III storage ring (Hamburg, Germany) using a Pilatus 1M-W detector at a sample-detector distance of 2.7 m and at a wavelength of λ = 0.15 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). Solute concentrations ranging between 0.4 and 7.3 mg/ml were measured at 10°C. Four successive 30 second frames were collected. The data were normalized to the intensity of the transmitted beam and radially averaged; the scattering of the solvent-blank was subtracted. The low angle data collected at lower concentrations were extrapolated to infinite dilution and merged with the higher concentration data to yield the final composite scattering curve.

Annexin-A4 (Annexin-A4)
Mol. type   Protein
Organism   Homo sapiens
Olig. state   Monomer
Mon. MW   36 kDa
Sequence   FASTA