(A) Coomassie stained SDS-PAGE gel of purified His6-hTpx2, His6-hKif15, and His6-hKif15-GFP. (B) Tetrameric His6-hKif15 on a 4–16% Native-PAGE gel stained with coomassie. Calculated molecular weight: His6-hKif15: 165 kDa. (C) Coomassie stained SDS-PAGE gels of fractions 1–23 out of 25 from 5–40% glycerol gradients loaded with either ∼5 µg His6-hKif15 or His6-hKif15-eGFP at different salt concentration (see table ‘below’ that summarises the apparent S values of hKif15(eGFP) at different salt concentrations). (D) Elution profile (grey line, A280, left y-axis) from a size-exclusion chromatography (SEC) run with subsequent multi angle light scattering (MALS) analysis. Outcome of the MALS analysis for the peaks is presented in coloured lines (blue-hKif15 tetramer, orange hKif15 dimer, MW, right y-axis). Molecular weight ± uncertainty is given above each peak. Please note that the presence of dimeric hKif15 species is specific to the protein preparation used in this experiment only (‘Materials and methods’). Standard preparations do not contain any significant proportion of dimeric hKif15 (see panels B and C this Figure).