title: Efficient solid phase synthesis of mixed Thr(P)-, Ser(P)- and Tyr(P)-containing phosphopeptides by "global" "phosphite-triester" phosphorylation.
abstract: The synthesis of the mixed Thr(P)/Tyr(P)-containing peptide, Ala-Thr(P)-Tyr(P)-Ser-Ala, was accomplished by "phosphite-triester" phosphorylation of the resin-bound Thr/Tyr-containing peptide using di-t-butyl N,N-diethylphosphoramidite as the phosphitylation reagent. The pentapeptide-resin was assembled by Fmoc/solid-phase peptide synthesis with the use of PyBOP as coupling reagent and the hydroxy-amino acids incorporated as side-chain free Fmoc-Tyr-OH and Fmoc-Thr-OH. "Global" bis-phosphorylation of the peptide-resin was accomplished by treatment with di-t-butyl N,N-diethylphosphoramidite/1H-tetrazole followed by m-chloroperoxybenzoic acid oxidation of the intermediate di-t-butylphosphite triester. Simultaneous peptide-resin cleavage and peptide deprotection was effected by treatment of the peptide-resin with 5% anisole/TFA and gave the Thr(P)/Tyr(P)-containing phosphopeptide in high yield and purity. In addition, the tyrosyl residue was found to be phosphitylated in preference to the threonyl residue since the phosphitylation of the pentapeptide-resin using only 1.1 equiv. of di-t-butyl N,N-diethylphosphoramidite gave Ala-Thr-Tyr(P)-Ser-Ala as the major product and both Ala-Thr(P)-Tyr(P)-Ser-Ala and Ala-Thr-Tyr-Ser-Ala as minor products.
mesh_terms: D000595:Amino Acid Sequence; D004952:Esters / Q000737:chemistry; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000138:chemical synthesis*; D010748:Phosphopeptides / Q000138:chemical synthesis*; D010766:Phosphorylation; D019000:Phosphotyrosine; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000138:chemical synthesis
chemical_list: D004952:Esters; D009842:Oligopeptides; D010748:Phosphopeptides; C078362:alanyl-phosphothreonyl-phosphotyrosyl-seryl-alanine; C078363:alanyl-threonyl-phosphotyrosyl-seryl-alanine; C078361:alanyl-phosphoseryl-phosphotyrosyl-seryl-alanine; D019000:Phosphotyrosine; D014443:Tyrosine