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X-ray synchrotron radiation scattering data from the mature version of α-DsbA2 from Wolbachia pipientis in 25 mM TRIS 150mM NaCl pH 7.5 were collected on the SAXS/WAXS beam line of the Australian Synchrotron (Melbourne, Australia) in a SEC-SAXS configuration using a 2D Photon counting Pilatus 1M-W pixel detector (I(s) vs s, where s = 4π sin θ/λ and 2θ is the scattering angle; λ=0.1127 nm). Approximately 100 uL of 19.8 mg/ml protein solution were injected onto a WTC-030S5 column at a flow rate of 0.5 ml/min. Five hundred successive 5 second frames were collected during the SEC-SAXS run. The peak of the elution profile occured at ~18 mins after the start of the run, and the protein scattering was taken as the average of 8 frames collected 35-75 seconds after the peak eluted (the radius of gyration dropped to ~27.6 Ang at the peak concentration of ~2.2 mg/ml, so data was averaged at a region where the concentration was lower and concentration dependent effects were not apparent). The concentration range corresponding to the averaged frames was ~0.35 - 1.15 mg/ml, and the average concentration was taken as ~0.75 mg/ml. The buffer was taken as the sum of 100 frames collected between 3-9 mins after the start of the run. The data were normalized to the intensity of the transmitted beam and radially averaged and the scattering of the solvent-blank was subtracted. The models and corresponding fits include those derived from dummy-atom modelling using DAMMIN (top) and rigid-body modelling using CORAL (bottom).
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s, nm-1
