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Pauli Exclusion by n→π* Interactions: Implications for Paleobiology
Jinyi Yang1, Volga Kojasoy1, Gerard J Porter1
1Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
ACS Central Science
|October 28, 2024
Summary
Ancient collagen
Area of Science:
- Biochemistry
- Structural Biology
- Paleontology
Background:
- Proteins, essential biological molecules, typically function in aqueous environments.
- Collagen, a crucial structural protein in animals, requires exceptional stability.
- Intact collagen has been found in dinosaur fossils, despite peptide bonds' short half-life in water.
Purpose of the Study:
- To investigate the physicochemical mechanisms behind collagen's remarkable resistance to hydrolysis.
- To understand how collagen preserves its integrity over geological timescales.
Main Methods:
- Utilized a combination of experimental techniques.
- Employed computational methods to analyze molecular interactions.
Main Results:
- Identified a protective mechanism involving main-chain acyl groups in collagen.
- Discovered that O···C=O n→π* interactions shield peptide bonds from hydrolysis.
- Observed these protective interactions across nearly all peptide bonds within the collagen triple helix.
Conclusions:
- The Pauli exclusion principle underlies the observed O···C=O n→π* interactions.
- These interactions provide a physicochemical basis for collagen's extraordinary resistance to degradation.
- This molecular protection mechanism likely explains the preservation of ancient collagen in fossils.
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