X‐ray structure and function of fibronectin domains two and three of the neural cell adhesion molecule L1

Guédez G, Loers G, Jeffries C, Kozak S, Meijers R, Svergun D, Schachner M, Löw C, The FASEB Journal 37(3) (2023) DOI

SASDPB6 – Fibronectin 2 and 3 of cell adhesion molecule L1 (L1CAM) expressed in HEK293S GnTI-

Neural cell adhesion molecule L1
MWexperimental 34 kDa
MWexpected 24 kDa
VPorod 68 nm3
log I(s) 7.09×103 7.09×102 7.09×101 7.09×100
Neural cell adhesion molecule L1 small angle scattering data  s, nm-1
ln I(s)
Neural cell adhesion molecule L1 Guinier plot ln 7.10×103 Rg: 2.8 nm 0 (2.8 nm)-2 s2
(sRg)2I(s)/I(0)
Neural cell adhesion molecule L1 Kratky plot 1.104 0 3 sRg
p(r)
Neural cell adhesion molecule L1 pair distance distribution function Rg: 2.9 nm 0 Dmax: 9.5 nm

Data validation


Fits and models


log I(s)
 s, nm-1
Neural cell adhesion molecule L1 DAMMIN model
Neural cell adhesion molecule L1 DAMFILT model

log I(s)
 s, nm-1
Neural cell adhesion molecule L1 CORAL model

Synchrotron SAXS data from solutions of fibronectin 2 and 3 of cell adhesion molecule L1 (L1CAM; expressed in HEK293S GnTI- cells) in 50 mM MES pH 6.5, 150 mM NaCl, 5% glycerol, were collected on the EMBL P12 beam line at PETRA III (DESY, Hamburg, Germany) using a Pilatus 6M detector at a sample-detector distance of 3 m and at a wavelength of λ = 0.124 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). In-line size-exclusion chromatography (SEC) SAS was employed. The SEC parameters were as follows: A 40.00 μl sample at 9 mg/ml was injected at a 0.35 ml/min flow rate onto a GE Superdex 200 Increase 5/150 column at 20°C. 2880 successive 0.250 second frames were collected through the column elution. 16 SAXS data frames from the top of a single SEC elution peak were selected for averaging. The data were normalized to the intensity of the transmitted beam and radially averaged; the scattering of the solvent-blank was subtracted.

The entry shows 1) the individual ab initio reconstruction, 2) the spatial reconstruction of the averaged model and 3) the rigid body model with the best fitting showing the two fibronectin domains in a bent conformation that differs to the elongated conformation seen in the crystal structure (PDB entry 8AFO or 8AFP). SEC-SAXS data were collected with the same parameters from three samples differing mainly in the glycosylation pattern (refer to SASBDB entries SASDPC6 and SASDPD6).

Neural cell adhesion molecule L1 (FN2FN3)
Mol. type   Protein
Organism   Homo sapiens
Olig. state   Monomer
Mon. MW   24.2 kDa
 
UniProt   P32004 (712-917)
Sequence   FASTA