Low-resolution structures of modular nanotransporters shed light on their functional activity

Khramtsov Y, Vlasova A, Vlasov A, Rosenkranz A, Ulasov A, Ryzhykau Y, Kuklin A, Orekhov A, Eydlin I, Georgiev G, Gordeliy V, Sobolev A, Acta Crystallographica Section D Structural Biology 76(12):1270-1279 (2020) DOI

SASDJZ7 – A modular diphtheria toxin/flavohemoprotein nanotransporter (MNT) fused to an epidermal growth factor ligand module (MNT-EGF)

Modular nanotransporter with an epidermal growth factor ligand module
MWexperimental 100 kDa
MWexpected 76 kDa
VPorod 161 nm3
log I(s) 1.90×10-2 1.90×10-3 1.90×10-4 1.90×10-5
Modular nanotransporter with an epidermal growth factor ligand module small angle scattering data  s, nm-1
ln I(s)
Modular nanotransporter with an epidermal growth factor ligand module Guinier plot ln 1.90×10-2 Rg: 4.2 nm 0 (4.2 nm)-2 s2
(sRg)2I(s)/I(0)
Modular nanotransporter with an epidermal growth factor ligand module Kratky plot 1.104 0 √3 sRg
p(r)
Modular nanotransporter with an epidermal growth factor ligand module pair distance distribution function Rg: 4.3 nm 0 Dmax: 16 nm

Data validation

Fits and models

log I(s)
 s, nm-1
Modular nanotransporter with an epidermal growth factor ligand module GASBOR model
Synchrotron SAXS data from solutions of MNT-EGF in 150 mM NaCl, 10 mM phosphate buffer saline, pH 8 were collected on the BM29 beam line at the ESRF (Grenoble, France) using a Pilatus 1M detector at a sample-detector distance of 2.9 m and at a wavelength of λ = 0.09918 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 500.00 μl sample at 4.2 mg/ml was injected at a 0.75 ml/min flow rate onto a GE Superdex 200 Increase 10/300 column at 20°C. 101 successive 1 second frames were collected through the SEC elution peak of the sample. The data were normalized to the intensity of the transmitted beam and radially averaged; the scattering of the solvent-blank was subtracted.

The first part of the amino acid sequence of MNT-EGF encompasses sequences homologous to Diphtheria toxin (https://www.uniprot.org/uniprot/P00587) followed by Flavohemoprotein (https://www.uniprot.org/uniprot/P24232). The C-terminal region has a sequence homology to Pro-epidermal growth factor (https://www.uniprot.org/uniprot/P01133).

Modular nanotransporter with an epidermal growth factor ligand module (MNT-EGF)
Mol. type   Protein
Organism   synthetic construct
Olig. state   Monomer
Mon. MW   76.3 kDa
Sequence   FASTA