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The low-energy conformations of gonadotropin-releasing hormone in aqueous solution.
- Source :
-
The protein journal [Protein J] 2014 Dec; Vol. 33 (6), pp. 565-74. - Publication Year :
- 2014
-
Abstract
- Using the chain-build-up method based on Empirical Conformational Energies of Peptides Program including solvation, we have computed, the low energy conformations of gonadotrpin-releasing hormone, GnRH, whose sequence is Pyro-Glu(PG)-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH2. We have found 5,077 solvated conformations with conformational energies that were within 5 kcal/mole of that of the global minimum. These minima were found to occur in 802 distinct conformational classes of which 25 represented 70 % of the Boltzmann energy-weighted structures. Virtually all of these structures adopted bend conformations from Tyr 5-Leu 8, and 3,861 structures adopted bend conformations at residues 4-7. However, these structures differed significantly from one another, indicating that GnRH does not adopt a well-defined structure in aqueous solution consistent with the absence of a well-defined NMR structure of GnRH in water. A total of 300 of these structures were found to be superimposable on possible NMR structures for GnRH in DMSO with a combined statistical weight of 1.6 %. We found that Gly 6 adopts low energy "starred" states, e.g., C* and D*, that are energetically forbidden to L-amino acids but are low energy for D-amino acids, with a statistical weight of 43 %. This can explain why substitutions of L-amino acids for Gly 6 are known to inactivate GnRH while D-amino acid substitutions enhance its activity. Using these findings, in the accompanying manuscript, we compute the low energy conformations for the substituted GnRHs that enable inference of possible receptor-bound conformations.
Details
- Language :
- English
- ISSN :
- 1875-8355
- Volume :
- 33
- Issue :
- 6
- Database :
- MEDLINE
- Journal :
- The protein journal
- Publication Type :
- Academic Journal
- Accession number :
- 25404067
- Full Text :
- https://doi.org/10.1007/s10930-014-9589-3