Synchrotron SAXS data from solutions of Metacaspase in 10 mM HEPES, 150 mM NaCl, 1% glycerol, 10 mM CaCl2, pH 7.6 were collected on the SWING beam line at SOLEIL (Saint-Aubin, France) using a Eiger 4M detector at a sample-detector distance of 2 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 50.00 μl sample at 9.6 mg/ml was injected at a 0.30 ml/min flow rate onto a GE Superdex 200 Increase 5/150 column at 10°C. 400 successive 1 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 expected MW quoted above (46 kDa) is of the full length protein, prior to self-cleavage into smaller components. These corresponding smaller products have an average MW of 20 kDa.
s, nm-1
