Efficient solution phase synthesis and use of multiple O-phosphothreonyl-containing peptides for calcium phosphate binding studies.
The protected phosphothreonine derivative Boc-Thr(PO3Ph2)-OH was prepared in high yield from Boc-Thr-OH by a simple three-step procedure which involved 4-nitrobenzylcarboxyl protection, either phosphorotriester (diphenyl phosphorochloridate) or "phosphite-triester" (diphenyl N,N-diethylphosphoramidite) phosphorylation of the threonine hydroxyl group of Boc-Thr-ONb followed by hydrogenolytic carboxyl deprotection. The three Thr(P)-containing peptides, H-Thr(P)-Glu-Glu-NHMe.TFA, H-Thr(P)-Thr(P)-Glu-Glu-NHMe.TFA and H-Thr(P)-Thr(P)-Thr(P)-Glu-Glu-NHMe.TFA, were prepared in high yield by the use of Boc-Thr(PO3Ph2)-OH in the Boc mode of peptide synthesis (mixed anhydride method) followed by platinum-mediated hydrogenolytic deprotection of the Thr(PO3Ph2)-containing peptides. The use of the phosphopeptides in calcium phosphate binding studies showed that the triple Thr(P)-cluster was a basic structural requirement, since only the pentapeptide was able to bind calcium phosphate efficiently.
Perich
J W
JW
Biochemistry and Molecular Biology Unit, School of Dental Science, University of Melbourne, Victoria, Australia.
Kelly
D P
DP
Reynolds
E C
EC
D000595:Amino Acid Sequence; D001665:Binding Sites; D002130:Calcium Phosphates / Q000737:chemistry*; D008722:Methods; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000138:chemical synthesis* / Q000737:chemistry; D010769:Phosphothreonine / Q000737:chemistry; D011485:Protein Binding; D012996:Solutions
D002130:Calcium Phosphates; D009842:Oligopeptides; D012996:Solutions; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; D010769:Phosphothreonine; C485838:calcium phosphate, monobasic, anhydrous; C020243:calcium phosphate; C485829:calcium phosphate, dibasic, anhydrous