Phosphorylation of serine, threonine and tyrosine is counted among the most important posttranslational modifications that occur in organisms.
Therefore, the preparation of synthetic phosphorylated peptides is of significant interest for researchers. However, those synthetic efforts are frequently hampered by the lability of the phosphoester bond.
Here we present three phosphono-amino acid derivatives that serve as hydrolysis-stable mimics of pSer, pThr and pTyr, termed Pma (Ser), Pmab (Thr) and Pmp (Tyr). Those derivatives are suitably protected for their use in peptide synthesis using the Fmoc strategy. The tert-butyl protecting groups on the phosphonic acid moieties prevent side reactions by this group and can be removed during final deprotection of the peptide.
Phosphoserine, -threonine and -tyrosine (left), and their phosphono-analogs Pma, Pmab and Pmp (right).
The stability towards hydrolysis that characterizes the phosphono-derivatives has an additional benefit, which is that cellular phosphatases are unable to remove the phosphate group mimic. Consequently, peptides or semi-synthetic proteins that include Pma, Pmab or Pmp are valuable tools for cell-based experiments.
- Phosphatase-stable phosphoamino acid mimetics that enhance binding affinities with the polo-box domain of polo-like kinase 1; D. Hymel and T. R. Burke, Jr.; ChemMedChem 2017; 12: 202-206. doi:10.1002/cmdc.201600574
- Analysis of Phosphorylation-Dependent Protein–Protein Interactions of Histone H3; R. Klingberg, J. O. Jost, M. Schümann, K. A. Gelato, W. Fischle, E. Krause and D. Schwarzer; ACS Chemical Biology 2015; 10: 138-145. doi:10.1021/cb500563n
- Effects on polo-like kinase 1 polo-box domain binding affinities of peptides incurred by structural variation at the phosphoamino acid position; W. Qian, J.-E. Park, F. Liu, K. S. Lee and T. R. Burke; Bioorg. Med. Chem. 2013; 21: 3996-4003. doi:10.1016/j.bmc.2012.05.036
- Serendipitous alkylation of a Plk1 ligand uncovers a new binding channel; F. Liu, J.-E. Park, W.-J. Qian, D. Lim, M. Gräber, T. Berg, M. B. Yaffe, K. S. Lee and T. R. Burke Jr; Nature Chemical Biology 2011; 7: 595. doi:10.1038/nchembio.614
- Cellular Stability of Serotonin N-Acetyltransferase Conferred by Phosphonodifluoromethylene Alanine (Pfa) Substitution for Ser-205; W. Zheng, D. Schwarzer, A. LeBeau, J. L. Weller, D. C. Klein and P. A. Cole; Journal of Biological Chemistry 2005; 280: 10462-10467. doi:10.1074/jbc.M412283200
- Large scale preparation of cell permeable, non-phosphate-containing Grb2 SH2 domain inhibitors; D.-G. Liu, Z.-J. Yao, Y. Gao and T. R. Burke, Jr.; Org. Prep. Proced. Int. 2000; 32: 197-201. doi:10.1080/00304940009356287
- Inhibition of Grb2 SH2 Domain Binding by Non-Phosphate-Containing Ligands. 2. 4-(2-Malonyl)phenylalanine as a Potent Phosphotyrosyl Mimetic; Y. Gao, J. Luo, Z.-J. Yao, R. Guo, H. Zou, J. Kelley, J. H. Voigt, D. Yang and T. R. Burke, Jr.; J. Med. Chem. 2000; 43: 911-920. doi:10.1021/jm9904248