Structural-functional diversity of malaria parasite's PfHSP70-1 and PfHSP40 chaperone pair gives an edge over human orthologs in chaperone-assisted protein folding.

Anas M, Shukla A, Tripathi A, Kumari V, Prakash C, Nag P, Kumar LS, Sharma SK, Ramachandran R, Kumar N, Biochem J 477(18):3625-3643 (2020) Europe PMC

SASDHU5 – Heat shock protein 70 (PfHSP70-1)

Heat shock protein 70
Peptide
MWexperimental 75 kDa
MWexpected 75 kDa
VPorod 450 nm3
log I(s) 1.08×105 1.08×104 1.08×103 1.08×102
Heat shock protein 70 Peptide small angle scattering data  s, nm-1
ln I(s)
Heat shock protein 70 Peptide Guinier plot ln 1.09×105 Rg: 5.3 nm 0 (5.3 nm)-2 s2
(sRg)2I(s)/I(0)
Heat shock protein 70 Peptide Kratky plot 1.104 0 √3 sRg
p(r)
Heat shock protein 70 Peptide pair distance distribution function Rg: 5.8 nm 0 Dmax: 16.6 nm

Data validation

Fits and models

log I(s)
 s, nm-1
Heat shock protein 70 Peptide DAMFILT model
SAXS data from solutions of Heat shock protein 70 (Hsp70) in 50mM Tris, 5mM MgCl2, 500mM KCl, 5mM Bme, 5% glycerol, pH 8 were collected using an Anton Paar SAXSpace instrument at the CSIR-Central Drug Research Institute (Lucknow, India) using a Mythen2 R 1K detector at a sample-detector distance of 0.3 m and at a wavelength of λ = 0.154 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). One solute concentration of 9.00 mg/ml was measured at 10°C. Two successive 1800 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.

The experimental molecular weight (74.8KDa) has been validated by size exclusion chromatography using Superdex 200 Increase 10/300 GL column (GE Healthcare). CAUTION! The model presented in this entry is a volume and bead-occupancy corrected visualization based on the spatial alignment of several individual bead model reconstructions and does not reflect the associated fit to the scattering data as presented in this entry. CAUTION! The estimated Porod volume is significantly larger than anticipated for a protein with a MW of 74.8 kDa.

Heat shock protein 70 (1-677)
Mol. type   Protein
Organism   Plasmodium falciparum
Olig. state   Monomer
Mon. MW   73.9 kDa
 
UniProt   Q8IB24
Sequence   FASTA
 
Peptide (NR)
Mol. type   Protein
Organism   synthetic construct
Olig. state   Monomer
Mon. MW   0.8 kDa
Sequence   FASTA