Influence of Proline on Secondary Structure in Peptides

A researcher is studying a novel peptide that is rich in proline and alanine residues. The peptide is hypothesized to play a significant role in structural stability due to the unique properties of its amino acid composition. The researcher is particularly interested in how the secondary structure of the peptide might be influenced by the presence of proline, known for its ability to induce kinks in polypeptide chains.

In order to understand the impact of proline on the peptide's conformation, the researcher performs a series of experiments, including circular dichroism spectroscopy, to assess secondary structure elements while varying the concentration of proline. The results indicate that increased concentrations of proline result in a significant reduction in alpha-helical content.

Taking this information into account, which amino acid characteristic primarily accounts for proline's influence on secondary structure?