Deciphering the ‘biological morse-code’: a preliminary ab initio study of phosphoserine

Abstract Exploratory ab initio conformational analysis has been carried out on phosphoserine (Pse) residue using formyl- l -serinamide-phopate-esther magnesium salt [HCO–NHCH(CH 2 OPO 3 Mg)–CONH 2 ]. On the basis of the computed stabilities it appeared that the Mg salt of For- l -Pse-NH 2 has greater flexibility than the unphosphorilated counter part: For- l -Ser-NH 2 .