Depsipeptides

Depsipeptides are peptides which, in addition to peptide bonds ( amide bonds ), also contain ester bonds .

Basic structure of a depsipeptide with three amide groups ( marked in blue ) and an ester group ( marked in green ). R ¹ and R ³ are the organic radicals customary for α-hydroxycarboxylic acids or a hydrogen atom . R ² , R ⁴ and R ⁵ are the organic radicals customary from the side chains of amino acids or a hydrogen atom.

Depsipeptides have been widely used to study the influence of hydrogen bonds on the kinetics and thermodynamics of protein folding . In this context, artificial peptide analogs have been created.

However, depsipeptides are also found in nature: One example of this is the L - Lys - D - Ala - D - Lac motif, which is found in the pentapeptide cell wall components of vancomycin- resistant bacteria . Replacing the amide group with an ester group prevents vancomycin from binding, rendering it ineffective. Further examples of natural depsipeptides are the antibiotics from the group of katanosins , the cryptophycins , the enniatins (see fusafungin ), arenastatin A , valinomycin , teixobactin or the didemnins . Most depsipeptides have a cyclic structure and are optically active, neutral, stable, crystalline substances. The amino acid building blocks of the depsipeptides are widely varied; the hydroxy acid often contains D- α-hydroxyisovaleric acid.

Individual evidence

1. ↑ Entry on depsipeptides . In: IUPAC Compendium of Chemical Terminology (the “Gold Book”) . doi : 10.1351 / goldbook.D01604 Version: 2.3.3.
2. ↑ Hans-Dieter Jakubke, Hans Jeschkeit: amino acids, peptides, proteins , Verlag Chemie, Weinheim, 103, 1982, ISBN 3-527-25892-2 .
3. ↑ Brockhaus ABC Chemie , VEB FA Brockhaus Verlag Leipzig 1965, pp. 275-276.