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Calculating three-dimensional molecular structure from atom-atom distance information: cyclosporin A
J Lautz1, H Kessler, J M Blaney
1Institute for Organic Chemistry, J.-W.-Goethe University, Frankfurt, F.R.G.
International Journal of Peptide and Protein Research
|April 1, 1989
Summary
Spatial molecular structure determination using atom-atom distance information from two-dimensional nuclear magnetic resonance (NMR) is advancing. Distance geometry and restrained molecular dynamics successfully elucidated cyclosporin A
Area of Science:
- Biochemistry and Structural Biology
- Computational Chemistry
- Molecular Biophysics
Background:
- Advancements in two-dimensional nuclear magnetic resonance (NMR) enable the acquisition of atom-atom distance information for biomolecules in solution.
- This distance data is crucial for determining the three-dimensional structures of peptides, proteins, sugars, and DNA fragments.
- Accurate spatial structure elucidation is vital for understanding molecular function and drug design.
Purpose of the Study:
- To compare the efficacy of Distance Geometry (DG) and restrained Molecular Dynamics (MD) refinement in determining molecular structure from experimental distance constraints.
- To validate these computational methods using a well-characterized cyclic polypeptide, cyclosporin A.
- To assess the relative strengths of DG and restrained MD for structure determination in solution.
Main Methods:
- Application of Distance Geometry (DG) algorithms to generate initial structural models based on NMR-derived distance restraints.
- Utilizing restrained Molecular Dynamics (MD) simulations to refine these models, incorporating experimental distance and stereochemical information.
- Comparing two distinct protocols: DG followed by restrained MD, and direct restrained MD from an existing X-ray structure.
Main Results:
- Both computational approaches, DG followed by restrained MD and straightforward restrained MD, converged to a single, unique molecular conformation for cyclosporin A.
- The determined structure satisfied all 58 experimentally derived distance constraints obtained from NMR data.
- The study demonstrated the successful application of these methods to a complex cyclic peptide.
Conclusions:
- Distance Geometry and restrained Molecular Dynamics are powerful, complementary techniques for solving molecular structures in solution using NMR-derived distance information.
- These methods provide a reliable means to determine unique conformations that are consistent with experimental data.
- The findings highlight the utility of these computational tools in structural biology and drug discovery.