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DOI: 10.1055/s-0031-1290119
Novel Phosphate Derivatives as Scaffolds for the Preparation of Synthetic Phosphoserine-Based Peptides Using the Fmoc/t-Bu Solid-Phase Strategy
Publikationsverlauf
Publikationsdatum:
22. Dezember 2011 (online)
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Abstract
Synthetic peptides incorporating analogues of phosphoserine are valuable tools for the study of protein kinases and phosphatases. In addition, derivatives of naturally occurring peptides incorporating phosphate groups may have interesting biological properties. Herein we describe a new Fmoc/t-Bu solid-phase peptide synthesis (SPPS) strategy for the convenient generation of phosphoserine-based peptides. A proof-of-concept synthesis that demonstrates the feasibility of this approach is presented.
Key words
phosphopeptide - serine - phosphorus - solid-phase synthesis - amino acids
- Supporting Information for this article is available online:
- Supporting Information
- 1
de bont DBA.Moree WJ.Vanboom JH.Liskamp RMJ. J. Org. Chem. 1993, 58: 1309 - 2
Wiemann A.Frank R.Tegge W. Tetrahedron 2000, 56: 1331 - 3 For example phosphoserine residues
are known to be sensitive to the strong acidic and basic conditions
typically employed in Fmoc SPPS. See:
Perich JW. Synthesis of Phosphopeptides, In Synthesis of Peptides and Peptidomimetics, Houben-Weyl Methods in Organic Chemistry Volume E22b: Thieme; Stuttgart: 2004. p.375-424 - 4
Singer D.Hoffman R. In Peptide-Based Drug Design, Methods in Molecular Biology Vol. 494:Otvos L. Humana Press; Totowa (NJ / USA): 2008. p.209 - 5
Shapiro G.Buechler D.Enz A.Pombovillar E. Tetrahedron Lett. 1994, 35: 1173 - 6
Wakamiya T.Nishida T.Togashi R.Saruta K.Yasuoka J.Kusumoto S. Bull. Chem. Soc. Jpn. 1996, 69: 465 - 7
Wakamiya T.Saruta K.Yasuoka J.Kusumoto S. Chem. Lett. 1994, 24: 1099 -
8a For
a recent discussion of the use of peptides and peptide derivative
as therapeutic agents, see:
Mason JM. Future Med. Chem. 2010, 2: 1813 -
8b For a recent general review of
the use of small molecules as tools to study biological systems,
see:
O’Connor CJ.Laraia L.Spring DR. Chem. Soc. Rev. 2011, 40: 4332 - 9
Shapiro G.Büchler D.Dalvit C.Frey P.Fernandez MdC.Gomez-Lor B.Pombo-Villar E.Stauss U.Swoboda R.Waridel C. Bioorg. Med. Chem. 1997, 5: 147 -
10a
Gorske BC.Blackwell HE. Org. Biomol. Chem. 2006, 4: 1441 -
10b
Lyon GJ.Wright JS.Muir TW.Novick RP. Biochemistry 2002, 41: 10095 -
12a
Barany G.Albericio F. J. Am. Chem. Soc. 1985, 107: 4936 -
12b
Isidro-Llobet A.Alvarez M.Albericio F. Chem. Rev. 2009, 109: 2455 -
13a It
is known that the stability of the phosphate moiety is increased
when the phosphate triester is replaced with the diester. In addition,
cyanoethyl group removal is generally quicker than serine β-elimination,
thus preventing it. See:
McMurray JS.Coleman DR.Wang W.Campbell ML. Biopolymers (Pept. Sci.) 2001, 60: 3 -
13b
Fmoc/t-Bu SPPS using derivatives of this sort as starting materials is superior to that employing the analogous compounds containing a free phosphoric acid group (see ref. 7).
-
14a
Galloway WRJD.Hodgkinson JT.Bowden SD.Welch M.Spring DR. Chem. Rev. 2011, 11: 28 -
14b
Hodgkinson JT.Galloway WRJD.Casoli M.Keane H.Su X.Welch M.Spring DR. Tetrahedron Lett. 2011, 52: 3291 -
14c
Hodgkinson JT.Galloway WRJD.Saraf S.Baxendale IR.Ley SV.Ladlow M.Welch M.Spring DR. Org. Biomol. Chem. 2011, 9: 57 -
14d
Hodgkinson JT.Bowden SD.Galloway WRJD.Spring DR.Welch M. J. Bacteriol. 2010, 192: 3833 - The use of 2-CTC resin allows the cleavage of peptide from the solid phase with 1-2% of TFA without removing any side-chain protecting groups that may be present within the main peptide, which could be important from the perspective of any post-cleavage synthetic manipulations. See:
-
15a
Benz H. Synthesis 1994, 337 -
15b
Barlos K.Chatzi O.Gatos D.Stavropoulos G. Int. J. Pept. Protein Res. 1991, 37: 513 -
15c An additional advantage
of the 2-CTC resin is that its hindered structure minimises the
formation of diketopiperazines during removal of the temporary protecting
group of the second amino acid on the solid phase (Scheme 4, 10 to 11, step
iv); see:
Rovero P.Vigano S.Pegoraro S.Quartara L. Lett. Pept. Sci. 1996, 2: 319 - 16
Subirós-Funosas R.Prohens R.Barbas R.El-Faham A.Albericio F. Chemistry 2009, 37: 9394 -
17a The
chloranil test for detection of primary and secondary amines was
performed after each solid-phase coupling reaction to confirm that
it had proceeded to completion. See:
Vojkovsky T. Peptide Res. 1995, 8: 236 -
17b
When the test was negative the Fmoc group was removed with piperidine-DMF (1:4); otherwise the Fmoc-amino acid was re-coupled under the same conditions. See Supporting Information for full details.
- For recent reviews on diversity-oriented synthesis, see:
-
22a
Galloway WRJD.Isidro-Llobet A.Spring DR. Nat. Commun. 2010, 1: 80 -
22b
Dandapani S.Marcaurelle LA. Curr. Opin. Chem. Biol. 2010, 14: 362 -
22c
Schreiber SL. Nature (London) 2009, 457: 153 -
22d
Nielsen E.Schreiber SL. Angew. Chem. Int. Ed. 2008, 47: 48 -
22e
Galloway WRJD.Bender A.Welch M.Spring DR. Chem. Commun. 2009, 2446
References and Notes
Drawbacks of typical on-resin phosphorylation methods include: difficulties with the incorporation of oxidation-sensitive residues, capriciousness and a general need for large excess of phosphorylation reagents and long reaction times (see ref. 9).
18t-Bu and Boc were chosen for either carboxylic (11) or amino (14) protection as they were stable to piperidine treatment, used to remove the Fmoc group, and to low concentrations of TFA, used to cleave the peptide from the 2-CTC resin (Scheme [4] ).
19It is noteworthy that compounds 2a and 2b, as well as the corresponding free carboxylic acids 9a and 9b, were obtained as diastereomeric mixtures. However, once the cyanoethyl group undergoes β-elimination during the basic treatment to remove the Fmoc group in SPPS (Scheme [4] ), the phosphorus centre is no longer chiral leading to only one stereoisomer of the desired phosphopeptide.
20HPLC analysis of the crude material obtained after workup revealed that the peptide was approx. 70% pure.
21The cyclised analogue of 1 is of interest; comparison of the biological
effects of the acyclic and cyclic variants would provide useful
information on the importance of the macro-cyclic ring structure
for the biological activity of these types of compounds. Preliminary
attempts at cyclising 1
via intramolecular
amide formation have provided some evidence for the formation of
the desired product. Studies towards the isolation and biological
testing of the cyclised analogue of 1 are
ongoing and will be reported in due course.