The structure of the apolipoprotein A-I monomer provides insights into its oligomerisation and lipid-binding mechanisms

Tou H, Rosenes Z, Khandokar Y, Zlatic C, Metcalfe R, Mok Y, Morton C, Gooley P, Griffin M, Journal of Molecular Biology :169394 (2025) DOI

SASDUC9 – Full-length apolipoprotein A-I in complex with antigen-binding fragment 55201

Apolipoprotein A-I
Antigen-binding fragment 55201
MWexperimental 54 kDa
MWexpected 73 kDa
VPorod 99 nm3
log I(s) 4.01×10-3 4.01×10-4 4.01×10-5 4.01×10-6
Apolipoprotein A-I Antigen-binding fragment 55201 small angle scattering data  s, nm-1
ln I(s)
Apolipoprotein A-I Antigen-binding fragment 55201 Guinier plot ln 4.01×10-3 Rg: 4.6 nm 0 (4.6 nm)-2 s2
(sRg)2I(s)/I(0)
Apolipoprotein A-I Antigen-binding fragment 55201 Kratky plot 1.104 0 √3 sRg
p(r)
Apolipoprotein A-I Antigen-binding fragment 55201 pair distance distribution function Rg: 4.8 nm 0 Dmax: 17.5 nm

Data validation

Fits and models

log I(s)
 s, nm-1
Apolipoprotein A-I Antigen-binding fragment 55201 COOT model
Synchrotron SAXS data from solutions of apolipoprotein A-I in complex with antigen-binding fragment 55201 in 20 mM Tris, 150 mM NaCl, 0.1% sodium azide, pH 7.4 were collected on the SAXS/WAXS beam line at the Australian Synchrotron (Melbourne, Australia) using a Pilatus3 S 2M detector at a wavelength of λ = 0.1078 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). One solute concentration of 7.00 mg/ml was measured at 20°C. Six 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.

Sample detector distance: UNKNOWN.

Apolipoprotein A-I (ApoA-I)
Mol. type   Protein
Organism   Homo sapiens
Olig. state   Monomer
Mon. MW   28.1 kDa
 
UniProt   P02647 (25-267)
Sequence   FASTA
 
Antigen-binding fragment 55201 (Fab 55201)
Mol. type   Protein
Organism   Mus musculus
Olig. state   Monomer
Mon. MW   44.8 kDa
Sequence   FASTA