Related Experiment Videos
Solution and structure of an alternating D,L-peptide
Eftichia Alexopoulos1, Andrea Küsel, George M Sheldrick
1Lehrstuhl für Strukturchemie, Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 4, 37077 Göttingen, Germany.
Acta Crystallographica. Section D, Biological Crystallography
|October 27, 2004
Summary
The crystal structure of a D,L-alternating peptide was determined, revealing a double-stranded antiparallel beta-helix. This finding advances our understanding of peptide crystallography and protein folding.
Area of Science:
- Structural biology
- Crystallography
- Peptide chemistry
Background:
- D,L-alternating peptides present unique structural challenges.
- Understanding their folding is crucial for biomolecular design.
Purpose of the Study:
- To determine the high-resolution crystal structure of H-(L-Tyr-D-Tyr)(4)-L-Lys-OH.
- To elucidate the folding and packing of D,L-alternating peptides.
Main Methods:
- X-ray crystallography
- Single Isomorphous Replacement with Anomalous Scattering (SIRAS)
- Molecular Replacement (MR) attempts
- Structure solution using SHELXD and SHELXE programs
Main Results:
- The peptide H-(L-Tyr-D-Tyr)(4)-L-Lys-OH was resolved to 1.3 A.
- A double-stranded, right-handed, antiparallel beta-helix conformation was identified.
- Experimental phasing was essential for structure determination, outperforming initial MR attempts.
Conclusions:
- The study provides the first detailed structural insight into this class of D,L-peptides.
- The identified beta-helix motif offers a novel structural paradigm in peptide science.
- Methodological insights were gained for solving similar complex peptide structures.