Synthesis of a Model for Phycocyanin with Respect to the Acid-Base Chemistry between Protein and Chromophore

Summary.

 Earlier investigations have shown that the cysteine adduct of phycocyanobilin dimethylester qualifies for intramolecular protonation [1]. In this context, the -Cys-Ala-Phe-Asp-tetrapeptide adduct of phycocyanobilin dimethylester was synthesized and examined for its protonation properties with respect to the zwitterionic interaction between chromophore and protein.