Figure 1. Specificity of the anti-pSer⁴²⁵ antibody.

(A) Sequence of the synthetic phosphopeptide that was covalently coupled to keyhole limpet haemocyanin and used for rabbit immunization. The sequence numbering represents amino acid position in the COS BTPC RcPPC4. The peptide was synthesized with an extra N-terminal cysteine residue to facilitate its conjugation. The seryl phosphorylation site is indicated. (B) Dot blots of various amounts of the synthetic phosphopeptide and corresponding dephosphopeptide were probed with the affinity-purified anti-pSer⁴²⁵ antibody in the presence and absence of 10 μg/ml of dephosphopeptide or corresponding phosphopeptide.