Figure 3
From: Rational identification and characterisation of peptide ligands for targeting polysialic acid
(a) Interaction of PSA-binding and non-binding peptides with PSA as assessed by fluorescence anisotropy titrations (solubility limit of PSA ~1.5 mM). Anisotropy values were transformed by subtraction of minimum FA values for each curve (approximately equivalent to anisotropies of free peptides) to enable comparative analysis between peptides. Error bars are excluded for clarity; experimental errors (standard deviations) are provided in Supplementary Table S2 along with non-adjusted anisotropy values. (b) Relationship of microarray “affinity” (intensity values) to peptide Bmax/KD (from FA assay). Open circles represent peptides excluded from determination of Pearson correlation coefficient due to higher imprecision in Bmax and KD from anisotropy curve fits for these peptides (criteria for exclusion: fit standard error of Bmax or KD > fit value); values for these peptides are represented for comparison of microarray intensities to other peptides. Microarray intensities represent the mean of three independent experiments, with triplicate measurements within each screen. FA KD’s are from at least two independent experiments, with at least triplicate measurements within each assay. Error from the assay with greater inter-assay variability (i.e., microarray screening) is shown (inter-assay standard deviation).
