Peptides isosterism

The retro-peptide bond is a true isosteric peptide bond surrogate and as such may offer an important tool to study topics such as the functional role of the peptide backbone in peptide hormone-receptor interactions, and modulation of metabolic stability and bioavailability. Partially modified retro-inverso-peptides (PMRI-peptides) (e.g., 2-4, 7 Scheme 1) result from a retro-inverso transformation of one or several peptide bonds in an amino- and carboxy-free peptide (e.g., 5 Scheme 1). Evidently, partial or exhaustive retro-inverso transformations result in the introduction of two non-amino acid residues into the... 

Hempel, J., Nilsson, K., Larsson, K., and Jornvall, H., Internal chain cleavage and product heterogeneity during Edman degradation of isosteric peptide analogs lacking the a-carbonyl function, EEBS Lett., 194, 333-337, 1986. 

Nucleophilic addition reactions to A -monoprotected a-amino aldehydes 1 (Table 20) represent the beginning of the worldwide interest in peptide isosteres for the preparation of certain specific enzyme inhibitors (e.g., aspartylproteinase inhibition). Some examples of this reaction type show a relatively low diastereofacial selectivity, especially when the reactions are per-... 

These oligomers for which synthetic routes have been developed, are formally obtained by either the introduction of a peptide bond isostere (e.g. y9-thiopeptides [263],... 

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