Figure 3.

(a) Dynamic light scattering. The peak corresponds to a hydrodynamic radius of 1.97 nm, equivalent to a molecular mass of 16.5 kDa. Polydispersity is 10%. Protein concentration was 0.2 mg ml⁻¹ (24 μM). (b) Static (Rayleigh) light scattering. A series of C.AhdI protein concentrations (0.099–0.493 mg ml⁻¹) were analysed by static light scattering. The plot of residual intensity is shown in blue, (K)(C)/R₉₀ is shown in red. The intercept on the (K)(C)/R₉₀ axis gives 1/M_r, from which we obtain M_r = 16804 ± 376 Da.