A novel polypeptide, poly( O -phospho- L -Ser), was synthesized through the following three steps: i) preparation of O -diphenylphospho- L -serine N -carboxyanhydride [Ser(PPh 2 ) NCA]; ii) polymerization of Ser(PPh 2 ) NCA; iii) removal of phenyl groups from poly[Ser(PPh 2 )]....