Recombinant expression and purification of Plasmodium heme detoxification protein in E. coli: Challenges and discoveries.

Singh R, Makde RD, Protein Expr Purif 236:106789 (2025) Europe PMC

SASDXF5 – Chaperone protein DnaK (E.coli) & recombinant Heme ligase (HDP) (P.fulciparum) protein complex

Chaperone protein DnaK
Heme ligase
MWexperimental 70 kDa
MWexpected 97 kDa
VPorod 83 nm3
log I(s) 2.76×10-1 2.76×10-2 2.76×10-3 2.76×10-4
Chaperone protein DnaK Heme ligase small angle scattering data  s, nm-1
ln I(s)
Chaperone protein DnaK Heme ligase Guinier plot ln 2.77×10-1 Rg: 3.8 nm 0 (3.8 nm)-2 s2
(sRg)2I(s)/I(0)
Chaperone protein DnaK Heme ligase Kratky plot 1.104 0 √3 sRg
p(r)
Chaperone protein DnaK Heme ligase pair distance distribution function Rg: 4.1 nm 0 Dmax: 13.8 nm

Data validation

Fits and models

log I(s)
 s, nm-1
Chaperone protein DnaK Heme ligase GASBOR model
Chaperone protein DnaK Heme ligase ALPHAFOLD model
log I(s)
 s, nm-1
Chaperone protein DnaK Heme ligase ALPHAFOLD model
SAXS data from solutions of Chaperone protein DnaK (E.coli) & recombinant Heme ligase (HDP) (P.fulciparum) protein complex in 20 mM Tris-Cl, 200 mM NaCl, pH 8 were collected on the Anton Paar SAXSpace instrument (Chemistry Division, Bhabha Atomic Research Centre, ​Indore, India) using a 1D Mythen2 R series and 2D EIGER R series HPC dete detector at a wavelength of λ = 1.5406 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). One solute concentration of 5.00 mg/ml was measured at 25°C. 100 successive 30 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

Chaperone protein DnaK
Mol. type   Protein
Organism   Escherichia coli (strain K12)
Olig. state   Unknown
Mon. MW   69.1 kDa
 
UniProt   P0A6Y8
Sequence   FASTA
 
Heme ligase (HDPpf)
Mol. type   Protein
Organism   Plasmodium falciparum (isolate 3D7)
Olig. state   Unknown
Mon. MW   28.1 kDa
 
UniProt   Q8IL04
Sequence   FASTA