Table 2.

Summary of SAXS and AUC data

Sample (molecular weight kDaa)	SAXSb							AUCc
	Rg (nm)	Dmax (nm)	Vp (nm3)	Molecular weight (kDa)	s20xw (S)	χs	χRB	s20,w (S)	Molecular weight (kDa)	$\bar{v}$ (ml g− 1)	% mono	Fc(M)	Fs, M	f/fmin	Axial ratio
fH12–13 (13.6)	2.2 ± 0.1	7.1 ± 0.5	20 ± 2.5	19 ± 2	1.6 ± 0.1	1.58	1.24	1.74 ± 0.03	16.8 ± 0.8	0.724	80 ± 1	1.33	1.20	1.00	1.00
fH11–14 (27.3)	3.1 ± 0.1	10.5 ± 0.5	38 ± 7	35 ± 4	2.5 ± 0.2	1.43	1.18	2.25 ± 0.04	26.5 ± 1.3	0.725	99 ± 1	1.42	1.48	1.23	4.75
fH10–15 (41.1)	3.1 ± 0.1	10.4 ± 0.5	68 ± 13	46 ± 6	3.4 ± 0.2	0.81	1.30	3.19 ± 0.05	40.5 ± 2.0	0.725	97 ± 1	1.35	1.37	1.14	3.39

^aMolecular weights calculated from sequence.

^bR_g, D_max, and V_p are the experimentally (SAXS) determined radius of gyration, maximum particle dimension, and hydrated particle volume, respectively. s_20xw is the sedimentation coefficient computed from the SAXS bead models. χ_s and χ_RB are the discrepancies between the experimental data and the computed scattering curves from the most typical ab initio and rigid-body models, respectively. The χ_RB shown for fH12–13 is the value of the best-fit NMR model to the SAXS data calculated using CRYSOL.

^cs_20,w, $\bar{v}$, and % mono are the experimentally (AUC) determined sedimentation coefficient, partial specific volume, and percent monomer in the sample, respectively. F_c(M) is the frictional ratio [calculated from the initial c(s^⁎) fit]. F_s,M is the frictional ratio calculated from the sedimentation coefficient and the known (from sequence) molecular mass. f/f_min is the component of the frictional ratio that can be attributed to shape, on the basis that for a non-extended ‘globular’ protein, a value F = 1.20 (default value in SEDFIT) is generally applicable (for the computation of f/f_min, the second and more reliable of the two estimates for f/f₀ has been divided by 1.20).