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. 1975 Aug;72(8):2891–2894. doi: 10.1073/pnas.72.8.2891

Aspartic acid racemization in tooth enamel from living humans.

P M Helfman, J L Bada
PMCID: PMC432884  PMID: 1059082

Abstract

The aspartic acid in human tooth enamel shows increasing racemization with age. This increase is not seen in the metabolically active protein hemoglobin. The rate constant for the racemization reaction of aspartic acid in human tooth enamel was found to be 8.29 X 10(-4) yr-1. This rate constant suggests that in any protein with a long in vivo lifetime, D-aspartic acid will accumulate with age (about 8% of total aspartic acid in enamel will be the D-enantiomer after 60 years). Thus, racemization may play some role in the aging process affecting metabolically stable tissues in long-lived homeotherms. Aspartic acid racemization in toogh enamel also provides a biochronological tool for assessing the age of living mammals.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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