Table 1.

Hydrodynamic parameters

Sample	$${\mathit{M}}_{\mathit{app}}^{\mathit{0}}$$ a	$${\mathit{S}}_{\mathit{20}\mathit{,}\mathit{w}}^{\mathit{0}}$$ b	$${\left(\frac{\mathit{f}}{{\mathit{f}}_{\mathit{0}}}\right)}_{\mathit{app}}$$ b	Mcalcc	Scalcc	$${\left(\frac{\mathit{f}}{{\mathit{f}}_{\mathit{0}}}\right)}_{\mathit{calc}}$$ c
Fab	51.2	3.7	1.4	48.4	3.81	1.22
Sirp	39.4	2.7	1.6	42.6	2.52	1.46
1:1 Complex	91.0d	4.8	1.5	91.0	4.85	1.42
2:2 Complex	Nd	Nd	Nd	182.0	7.25	1.48

^acalculated using SEDANAL. Units are in kilodaltons.

^bdetermined from sedimentation velocity. Units are in S.

^ccalculated from the PDB file using US-SOMO. Units are the same for the observed parameters.

Nd not determined.