I would agree with Steve Johnson, except I've generally used PyBOP or
PyBrOP with DIEA in DMF and/or DMSO. When you come to the more complex
peptides, it's useful to have a residue that you can link via the side
chain (Asp, Asn, Glu, Gln) and cyclise head-to-tail while still on the
resin. Be careful of your choice of linkers though - I've had good success
with the safety-catch amide linker with side chain Asn or Gln on the resin.
Good luck!
Roger
At 12:03 PM 28-05-99 -0700, you wrote:
>Hi All,
>
>I would love some advice on head-to-tail cyclization methods for small
>synthetic
>peptides.I am in the process of synthesizing my first cyclic peptide. This
>particular peptide is very simple, a pentaGly, but I will be soon be
>synthesizing more complex cyclic peptides. The peptide is currently on a
>chlorotrityl resin. I am planning to cleave the peptide from the resin and
>then
>cyclize, but I suppose I could try on-resin methods of cyclization.
>
>Could you please enlighten me as to the most effective current cyclization
>methods. Thank you in advance.
>
>Kathy Schegg
>University of Nevada, Reno
>schegg@med.unr.edu
>(775) 784-4058
>(775) 784-1419 Fax
------------------------------------------------------------
Roger Murphy, Ph.D.
Biological Production Facility
Ludwig Institute for Cancer Research
Austin & Repatriation Medical Centre
Studley Road,
Heidelberg, Vic. 3084
Australia.
Tel 61-3-94965463
Fax 61-3-94965436
Email Roger.Murphy@Ludwig.edu.au