Washington, Dec 22 (IANS) Proline, a simple amino acid that recurs at the centre of proteins found in tooth enamel, makes teeth stronger and more resilient, according to a new research.

University of Illinois-Chicago (UI-C) researchers compared proline repeats in amphibian and animal models and discovered that when the repeats are short, such as in frogs, teeth will not have the enamel prisms that are responsible for the strength of human enamel.

Conversely, when the proline repeats are long, they contract groups of molecules that help enamel crystals grow.

'Proline repeats are amazing,' said study leader Tom Diekwisch, professor and head of oral biology at the UI-C College of Dentistry.

The new discovery, Diekwisch said, will give new clues to engineer tooth enamel. 'We hope that one day these findings will help people replace lost parts of the tooth with a healthy layer of new enamel.'

Diekwisch's team discovered that the longer the stretch of proline repeats, the more the protein bubbles contracted. The study also showed that the smaller protein bubbles were associated with longer enamel crystals, he said, according to a university release.

The findings were published in the Monday online version of the PLoS Biology.