Figure 2.

Sedimentation equilibrium studies of MinLeu and its variants indicate that all species are monomeric. Representative data for native MinLeu (native disulfide bonds) are plotted as ln(absorbance) against the square of the radius from the axis of rotation. The slope is proportional to the molecular weight: dashed lines indicate calculated slopes for monomeric and dimeric species. Deviations from the calculated values are plotted as residuals (Upper). The composite ratio (of all data sets for a given species) of observed-to-expected molecular weights for native MinLeu, nonnative disulfide isomer [6–28; 111–120], nonnative isomer [6–111; 28–120], and the alanine variant are 1.07, 1.08, 1.10, and 1.10, respectively.