Structure-based screening of binding affinities via small-angle X-ray scattering

Chen P, Masiewicz P, Perez K, Hennig J, (2019) DOI

SASDFG8 – Glutamine-binding periplasmic protein with hexahistidine tag (GlnBP) in the presence of glutamine - Gln-bound 10-fold excess

Glutamine-binding periplasmic protein with hexahistidine tag
MWexperimental 25 kDa
MWexpected 26 kDa
VPorod 34 nm3
log I(s) 4.96×101 4.96×100 4.96×10-1 4.96×10-2
Glutamine-binding periplasmic protein with hexahistidine tag small angle scattering data  s, nm-1
ln I(s)
Glutamine-binding periplasmic protein with hexahistidine tag Guinier plot ln 4.97×101 Rg: 2.0 nm 0 (2.0 nm)-2 s2
(sRg)2I(s)/I(0)
Glutamine-binding periplasmic protein with hexahistidine tag Kratky plot 1.104 0 3 sRg
p(r)
Glutamine-binding periplasmic protein with hexahistidine tag pair distance distribution function Rg: 2.0 nm 0 Dmax: 6.1 nm

Data validation


There are no models related to this curve.

Synchrotron SAXS data from solutions of GlnBP with a 10-fold excess of glutamine in 100 mM NaCl, 20 mM NaPO4, 0.5 mM TCEP, pH 7.4 were collected on the BM29 beam line at the ESRF (Grenoble, France) using a Pilatus 1M detector at a sample-detector distance of 2.8 m and at a wavelength of λ = 0.09919 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). One solute concentration of 2.00 mg/ml was measured at 20°C. 12 successive 2 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.

Gln-bound GlnBP at a ligand:protein ratio of 10:1. Ligand condition is prepared by dissolving glutamine in powder form (Sigma-Aldrich) directly into the SAXS buffer, followed by dilution to the target concentration with additional SAXS buffer.

Glutamine-binding periplasmic protein with hexahistidine tag (GlnBP)
Mol. type   Protein
Organism   Escherichia coli
Olig. state   Monomer
Mon. MW   25.8 kDa
 
UniProt   P0AEQ3 (23-248)
Sequence   FASTA