Solution structure of Plasmodium falciparum Hsp90 indicates a high flexible dimer

Silva N, Torricillas M, Minari K, Barbosa L, Seraphim T, Borges J, Archives of Biochemistry and Biophysics :108468 (2020) DOI

SASDHD9 – Full-length Plasmodium falciparum Heat shock protein 90 (PfHsp90)

Plasmodium falciparum Heat shock protein 90
MWexperimental 186 kDa
MWexpected 177 kDa
VPorod 350 nm3
log I(s) 3.54×106 3.54×105 3.54×104 3.54×103
Plasmodium falciparum Heat shock protein 90 small angle scattering data  s, nm-1
ln I(s)
Plasmodium falciparum Heat shock protein 90 Guinier plot ln 3.55×106 Rg: 5.7 nm 0 (5.7 nm)-2 s2
(sRg)2I(s)/I(0)
Plasmodium falciparum Heat shock protein 90 Kratky plot 1.104 0 √3 sRg
p(r)
Plasmodium falciparum Heat shock protein 90 pair distance distribution function Rg: 5.8 nm 0 Dmax: 19 nm

Data validation

Fits and models

log I(s)
 s, nm-1
Plasmodium falciparum Heat shock protein 90 DAMMIN model
Plasmodium falciparum Heat shock protein 90 DAMFILT model
Synchrotron SAXS data from solutions of full-length P. falciparum Heat shock protein 90 (PfHsp90) in 25 mM Tris-HCl, 100 mM KCl, 1 mM β-mercaptoethanol, 1 mM EDTA, pH 7.5 were collected on the SAXS1 Beamline beam line at the Brazilian Synchrotron Light Laboratory (Campinas, Brazil) using a Pilatus 300K detector at a sample-detector distance of 1 m and at a wavelength of λ = 0.1448 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). Solute concentrations ranging between 1 and 2.9 mg/ml were measured at 20°C. The data were normalized to the intensity of the transmitted beam and radially averaged; the scattering of the solvent-blank was subtracted. The low angle data collected at lower concentration were merged with the highest concentration high angle data to yield the final composite scattering curve.

Samples were measured for 6 x 10 seconds , 1 x 100 seconds and 1 x 300 second frames. The PfHsp90 sample concentrations were 1.0, 1.9 and 2.9 mg/mL. Data analysis was performed using the ATSAS 2.7.2 program. Ab initio modeling was performed using the DAMMIN program. Average of DA models was done by the DAMAVER package. Further refinement was done using the DAMMIN program.

Plasmodium falciparum Heat shock protein 90 (PfHsp90)
Mol. type   Protein
Organism   Plasmodium falciparum
Olig. state   Dimer
Mon. MW   88.3 kDa
 
UniProt   Q8IC05 (1-745)
Sequence   FASTA