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X-Ray Crystallography to Study the Oligomeric State Transition of the Thermotoga maritima M42 Aminopeptidase TmPep1050
Published on: May 13, 2020
Intramolecular ditryptophan crosslinks enforce two types of antiparallel beta structures
J H Matthews1, T D Dinh, P Tivitmahaisoon
1Department of Chemistry, University of California, Irvine, CA 92697-2025, USA.
Chemistry & Biology
|December 4, 2001
Summary
Ditryptophan crosslinks, similar to disulfide bonds, influence peptide structure. These biaryl crosslinks favor antiparallel beta-sheet formation in peptides, particularly when hydrogen bonding is optimized.
Area of Science:
- Biochemistry
- Structural Biology
- Peptide Chemistry
Background:
- Two natural biaryl crosslinks, ditryptophan and dityrosine, can form in proteins.
- Biaryl crosslinks share topology with disulfide crosslinks.
- The impact of biaryl crosslinks on local peptide structure remains largely uncharacterized.
Purpose of the Study:
- To investigate the structural effects of ditryptophan crosslinks in model peptides.
- To determine if ditryptophan crosslinks influence secondary structure formation.
Main Methods:
- Synthesis of three ditryptophan-linked peptide dimers with varying termini (Ac-Leu-Trp-Ala-COX).
- Crystallization and structural analysis of the peptide dimers.
- Solubility assessment of different peptide dimer derivatives.
Main Results:
- One tripeptide dimer derivative was insoluble.
- A ditryptophan-linked peptide dimer with methyl ester termini crystallized as an antiparallel beta-sheet.
- Another dimer derivative adopted a slipped antiparallel beta structure.
Conclusions:
- Intermolecular ditryptophan crosslinks can promote antiparallel beta-sheet structures in peptides.
- The preference for antiparallel beta-sheet structure is enhanced by optimal hydrogen bonding capabilities at the dimer edges.
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