Thesis final - after defense-7 - Jacobs University

Chapter 3
Figure 15 C: Represents the average hydrophobicity calculated by the scale of Tanford. The
protein average hydrophobicity values of the three ligands were correlated with the respective
salt concentrations where the fractions were collected. The error bars represent the standard
deviations of the average hydrophobicity values in each fraction. The statistical analysis
revealed a significant correlation (r 2 = 0.79; p < 0.0001).
Some proteins were observed to have similar values of average hydrophobicity but differed
with the average surface hydrophobicity (ASH). In this case, the protein with high ASH was
retained longer than the one with less ASH, although they have the same average
hydrophobicity. This revealed that ASH has a more decisive role in HIC than average
hydrophobicity. Although ASH is the most precise method, but the trends observed in case of
average hydrophobicity cannot be ignored. The reason for this could be that, although amino
acids on the surface are deciding for retention, the unfolding of proteins may occur during
chromatography experiments resulting in the retention based on the total hydrophobicity of a
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