A conformational fingerprint for amyloidogenic light chains

Paissoni C, Puri S, Broggini L, Sriramoju M, Maritan M, Russo R, Speranzini V, Ballabio F, Nuvolone M, Merlini G, Palladini G, Hsu S, Ricagno S, Camilloni C, (2025) DOI

SASDVK4 – Immunoglobulin light chain AL55

Immunoglobulin light chain AL55

MW^experimental	47	kDa
MW^expected	47	kDa
V^Porod	61	nm³

log I(s) 9.21×10¹ 9.21×10⁰ 9.21×10^-1 9.21×10^-2

Immunoglobulin light chain AL55 small angle scattering data

s, nm^-1

Log plot Log-Log plot

ln I(s)

Immunoglobulin light chain AL55 Guinier plot

ln 9.21×10¹ R_g: 2.6 nm 0 (2.6 nm)^-2 s²

(sR_g)²I(s)/I(0)

Immunoglobulin light chain AL55 Kratky plot

1.104 0 √3 sR_g

p(r)	R_g: 2.6 nm 0 D_max: 8.5 nm

Data validation

Experimental data range

p(r) fit to data

Metric

Value

s_min D_max / π

0.3

N_Shannon

Worse

Better

Metric

Value

p_cormap

χ²

0.130
1.139

Worse

Better

Fits and models

log I(s)	s, nm^-1
+3 Δ/σ -3	s, nm^-1

Immunoglobulin light chain AL55 SWISSMODEL model

Synchrotron SAXS data from solutions of immunoglobulin light chain AL55 in 20 mM TrisHCL, 150 mM NaCl, pH 8 were collected on the BM29 beam line at the ESRF (Grenoble, France) using a Pilatus3 2M detector at a sample-detector distance of 2.8 m and at a wavelength of λ = 0.099 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). One solute concentration of 2.60 mg/ml was measured at 10°C. 20 successive 0.050 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.

Immunoglobulin light chain AL55 (AL55)
Mol. type		Protein
Organism		Homo sapiens
Olig. state		Dimer
Mon. MW		23.3 kDa
Sequence		FASTA