Atomistic scattering modelling of the solution structure of human dimeric IgA1 reveals a structural and mechanistic basis for IgA nephropathy.

Bhatt JS, Yeo SC, Ireland SM, Ben-Younis A, Gor J, Molyneux K, Barratt J, Perkins SJ, J Biol Chem :113156 (2026) Europe PMC

SASDYZ2 – IgA1 dimer - Patient C

Human immunoglobulin IgA1
MWexperimental 314 kDa
MWexpected 320 kDa
log I(s) 1.00×100 1.00×10-1 1.00×10-2 1.00×10-3
Human immunoglobulin IgA1 small angle scattering data  s, nm-1
ln I(s)
Human immunoglobulin IgA1 Guinier plot ln 1×100 Rg: 8.5 nm 0 (8.5 nm)-2 s2
(sRg)2I(s)/I(0)
Human immunoglobulin IgA1 Kratky plot 1.104 0 √3 sRg
p(r)
Human immunoglobulin IgA1 pair distance distribution function Rg: 9.1 nm 0 Dmax: 35 nm

Data validation

Fits and models

log I(s)
 s, nm-1
Human immunoglobulin IgA1 CUSTOM IN-HOUSE model
Synchrotron SAXS data from solutions of IgA1 dimer - Patient C in PBS buffer, 137 mM NaCl, 8.2 mM Na2HPO4, 2.6 mM KCl, 1.5 mM KH2PO4, pH 7.4 were collected on the BM29 beam line at the ESRF storage ring (Grenoble, France) using a Pilatus 1M detector at a sample-detector distance of 2.9 m and at a wavelength of λ = 0.09919 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). Solute concentrations ranging between 0.3 and 1.3 mg/ml were measured at 20°C. 10 successive 1 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.

CAUTION: Errors associated with the scattering data points are not available.

Human immunoglobulin IgA1 (IgA1)
Mol. type   Protein
Olig. state   Dimer
Mon. MW   160 kDa
Sequence   FASTA