Figure 1.

Determining a PPARβ/δ interfering peptide by SPOT synthesis. (a) General concept of the SPOT synthesis to synthesize membrane-bound peptides and of their protein incubation followed by antibody detection. (b) TF65 PepScan: primary sequence of the TF65 protein was dissected in overlapping peptides (15-mer with a shift of 3 amino acids) which were synthesized on the chemically modified cellulose membrane. Peptides were incubated with the His-tagged PPARβ/δ protein revealing a potent epitope corresponding to the spots n°24-25 (orange square). (c) Length analysis of the 18-mer peptide (spots n°24-25, cut at N- and C-terminus) showed the minimal peptide length (12-mer peptide of spot n°8, orange circle) required for TF65 binding. (d) Substitutional analysis of the 12-mer PP11 peptide revealed four key positions corresponding to the amino acids of isoleucine, leucine, lysine, and arginine (see arrows).