Fig 2.

SAA2.2 exists as a mixture of hexamer–monomer in equilibrium. (A) Sedimentation-velocity profiles of a 0.27 mg/ml sample of SAA2.2. Scans for analysis were recorded every 1 min; for clarity only eight representative scans 3 min apart are shown. The velocity data exhibit two resolvable boundaries, one corresponding to the monomer and the second boundary corresponding to hexamer. (B) Analysis of the sedimentation profiles in A using the time-derivative method (dc/dt) reveals the presence of two sedimenting species with an average sedimentation coefficient of 1.5 (±1) and 5.4 S (±1). The solid line represents a two-species fit of the data (o) using a Gaussian function.