Influence of cis-trans isomerisation on pentapeptide cyclisation

Cyclisation reactions on pentapeptides containing the turn promoting residues Gly and Pro are investigated. Although the cyclisation reaction is fast, solvent-dependent mixtures of cyclic penta- and decapeptides are observed. NMR studies suggest a strong dependence of the monomer/dimer ratio on the cis-trans isomerisation found in linear and cyclic peptides. The critical influence on ring closure of a cis Xaa-Pro peptide bond conformation is demonstrated by using the cis peptide bond-inducing residue 2,2-dimethyl-1,3-thiazolidine-4 carboxylic acid (Dmt, pseudo-proline) as proline substitute. The results shed new light on the role of cis-trans isomerisation in pentapeptide cyclisation. (C) 1999 Elsevier Science Ltd. All rights reserved.


Published in:
Tetrahedron Lett., 40, 45, 7987-7991
Year:
1999
ISSN:
0040-4039
Laboratories:




 Record created 2006-02-09, last modified 2018-01-27


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