Hydrocarbon Stapling is achieved via incorporation of non-natural amino acids. Typically two α-methyl, α-alkenyl containing amino acids are used to generate crosslinks with the α,α-disubstituted amino acids bearing olefinic chains of variable lengths at positions ''i'' and "i+3" or ''i'' and ''i+4'' or ''i'' and ''i+7'' (where “i” represents the first staple position) along the peptide sequence. This is followed by ring closure, deprotection and cleavage of the peptide from the solid support.
In i & i+3 stapled peptides, there are two amino acids between the staples.
Inhibition of nutlin-resistant HDM2 mutants by stapled peptides.
Wei SJ, Joseph T, Chee S, Li L, Yurlova L, Zolghadr K, Brown C, Lane D, Verma C, Ghadessy F.
PLoS One. 2013;8(11).
DOI : 10.1371/journal.pone.0081068
From AnaSpec (Eurogentec's US subsidiary) : Stapled peptides (sTIP) with an (i, i + 3) hydrocarbon linkage were generated by replacing the respective amino acids with the olefin-bearing unnatural amino acids (R)-2-(4′pentenyl) alanine and (S)-2-(4′-pentenyl) alanine and stapled, via olefin metathesis, using the Grubbs catalyst.
In i & i+4 stapled peptides, there are three amino acids between the staples.
i & i+4 stapled peptides generate the most optimally stabilized pattern
Membrane permeability of hydrocarbon-cross-linked peptides
Sun TL, Sun Y, Lee CC, Huang HW.
Biophysical journal. 2013 May 7;104(9):1923-32.
DOI : 10.1016/j.bpj.2013.03.039
From AnaSpec (Eurogentec's US subsidiary) : NYAD-2 is FITC - (beta - Ala) - Ile - Thr - Phe - X - Asp - Leu - Leu - X - Tyr - Tyr - Gly - Pro - NH2 (with special cyclization to get double bond, X = (S) - alpha - (2′- pentenyl)alanine; FITC = fluorescein isothiocyanate)
In i & i+7 stapled peptides, there are six amino acids between the staples.
Structure of a stapled peptide antagonist bound to nutlin-resistant Mdm2.
Chee SM, Wongsantichon J, Tng QS, Robinson R, Joseph TL, Verma C, Lane DP, Brown CJ, Ghadessy FJ.
PLoS One. 2014;9(8).
DOI : 10.1371/journal.pone.0104914
From AnaSpec (Eurogentec's US subsidiary) : The (i, i +7) hydrocarbon linkage was generated by placing the olefin-bearing unnatural amino acids (S)-2-(49pentenyl) alanine and (S)-2-(79-octenyl) alanine at positions 4 and 11, respectively.
The design of stapled peptides follows incorporation of non-natural amino acids at specific sites along the desired peptide to form the "staples" (hydrocarbon cross-link).
- Length : Up to 60 amino acids.
- Purity : >95%, >90%, >85%, >70% or crude
- Quantity : 1 mg minimum up to gram quantities, delivered as gross weight or net weight.