Solution structural studies of pre-amyloid oligomer states of the biofilm protein Aap.

Yarawsky AE, Hopkins JB, Chatzimagas L, Hub JS, Herr AB, J Mol Biol :167708 (2022) Europe PMC

SASDP53 – Accumulation-association protein (Aap) Brpt5.5 5xH85A monomer

Accumulation associated protein (mutant)
MWexperimental 71 kDa
MWexpected 78 kDa
log I(s) 1.92×10-2 1.92×10-3 1.92×10-4 1.92×10-5
Accumulation associated protein (mutant) small angle scattering data  s, nm-1
ln I(s)
Accumulation associated protein (mutant) Guinier plot ln 1.93×10-2 Rg: 14.1 nm 0 (14.1 nm)-2 s2
Accumulation associated protein (mutant) Kratky plot 1.104 0 3 sRg
Accumulation associated protein (mutant) pair distance distribution function Rg: 15.5 nm 0 Dmax: 57.2 nm

Data validation

Fits and models

log I(s)
 s, nm-1
Accumulation-association protein (Aap) Brpt5.5 5xH85A monomer Rg histogram Rg, nm
Accumulation associated protein (mutant) OTHER model

Synchrotron SAXS data from solutions of accumulation-association protein (Aap) Brpt5.5 5xH85A monomer in 50 mM MOPS, 50 mM NaCl, pH 7.2 were collected on the BioCAT 18ID beam line at the Advanced Photon Source (APS), Argonne National Laboratory (Lemont, IL, USA) using a Pilatus3 X 1M detector at a sample-detector distance of 3.6 m and at a wavelength of λ = 0.1033 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 275.00 μl sample at 10.1 mg/ml was injected at a 0.80 ml/min flow rate onto a GE Superose 6 Increase 10/300 column at 23°C. 2871 successive 0.500 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.

Brpt5.5 5xH85A (G5 08 - G5 13). This is a mutant construct which contains a His to Ala mutation in the 85 position of each spacer subdomain.

Accumulation associated protein (mutant) (Aap)
Mol. type   Protein
Organism   Staphylococcus epidermidis (strain ATCC 35984 / RP62A)
Olig. state   Monomer
Mon. MW   77.7 kDa
UniProt   Q5HKE8 (1505-2223)
Sequence   FASTA