Dear Marcus:
Oligo-Leu should not be very difficult to synthesize, at least using Boc
chemistry.
Actually, in 1980 Kent SBH and Merrifield RB reported problem-free
assembly of
Boc-(Ile)12-PS using symmetrical anhydrides in DCM and single coupling
protocol (In: Peptides 1980, 328-33).
Next, Narita et al synthesized model Boc-(Leu)n-Phe-PS resins (n=3-21);
FT-IR data revealed the beta-sheet conformation for n = 6-18, but no
serious problems were encountered.
We have recorded swelling dynamics in the synthesis of the same peptide
resin and found that aggregation in this case is not severe and the
beta-sheet structure is easily disrupted in 20%TFE in DCM. Notably, this
solvent system has no effect at all on aggregated oligo-Ala resins which
swell reasonably only in 50%TFA-DCM.
Narita, M., Isokawa, S., Tomotake, Y., and Nagasawa, S. Synthesis and
the Solid-State Conformations of Cross-Linked Resin-Bound
Oligo(leucine)s. Internal Aggregations Through the Intermolecular
Hydrogen Bonding of the Oligopeptides on the Polymer Networks.- Polymer
Journal 1983, v.15, n.1, pp.25-32.
Narita,M., Ishikawa,K. and Nakano,H. and Isokawa,S. Tertiary peptide
bond containing-oligo(Leu)s. Conformational studies in solution of oligo
(L-leucine)s with L-proline residue and
glycyl-N-(2,4-dimethoxybenzyl)-L-leucine sequence..- Int.J.Pept.Protein
Res., 1984, v.24(1) , pp.14-24.
Narita,M., Fikunaga,T., Wakabayashi,A. and Ishikawa,K. and Nakano,H.
Syntheses and properties of tertiary peptide bond-containing
polypeptides. I. Syntheses and properties of oligo-(L-leucine)s
containing proline or glycyl-N-(2,4-dimethoxybenzyl)-L-leucine
residues..- Int.J.Pept.Protein Res., 1984, v.23(3) , pp.306-314.
I hope this information will be helpful.
Regards,
Igor Rodionov
Laboratory of Peptide Chemistry
Branch of Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry
8 Science Avenue, Pushchino, Moscow Region
142290, Russian Federation
rodionov@fibkh.serpukhov.su
This archive was generated by hypermail 2b29 : Mon Oct 23 2000 - 10:23:17 EDT