Bioorganic chemists in China have made peptide-like molecules that could aid the search for new medicines.

Dan Yang and co-workers studied oligomers of aminoxy acids, amino acid analogues that have an oxygen atom inserted next to the amino group. The researchers from the University of Hong Kong found that these short polymers display regions of well-defined structure, so-called secondary structures, such as helices, reverse turns and sheets.

Secondary structures are not usually found in natural peptides with less than about ten residues. In contrast, Yang and her co-workers discovered that aminoxy acid peptides with as few as two residues can form helices.

The oligomers form structures such as turns and helices due to hydrogen bonding between amino and keto groups in the backbone; the side chains do not contribute. According to the researchers, this means that peptides could be made that contain a variety of functional side groups yet still form these well-defined structures. 

Samuel Gellman of the University of Wisconsin, US, praised Yang for having established 'a clear set of folding rules' for aminoxy acid oligomers. 'The results are fascinating,' said Gellman.

Yang suggested that the oligomers could be used in drug discovery as models for studying interactions between peptides and proteins. Understanding these interactions is important in the design of new drugs, 'but these peptides could also be used as drugs themselves,' said Yang.

Danièle Gibney