Comparative conformational analysis and in vitro pharmacological evaluation of three cyclic hexapeptide NK-2 antagonists
| Autor: | Dieter Leibfritz, Roger M. Brunne, G. Hölzemann, U. Wollborn, J. Harting |
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| Rok vydání: | 2009 |
| Předmět: |
Magnetic Resonance Spectroscopy
Stereochemistry Molecular Sequence Data Molecular Conformation Peptide Peptides Cyclic Biochemistry Structure-Activity Relationship Molecular dynamics Cricetinae Tachykinins Animals Computer Simulation Amino Acid Sequence Beta (finance) Receptors Tachykinin chemistry.chemical_classification Antagonist Biological activity Nuclear magnetic resonance spectroscopy In vitro Cyclic peptide Receptors Neurotransmitter Trachea Models Chemical chemistry Thermodynamics |
| Zdroj: | International Journal of Peptide and Protein Research. 41:376-384 |
| ISSN: | 0367-8377 |
| DOI: | 10.1111/j.1399-3011.1993.tb00453.x |
| Popis: | The conformational analysis of three cyclic hexapeptides is presented. Cyclo-(-Gln6-Trp7-Phe8-Gly9-Leu10-D-Met11-) (1) and cyclo-(-Gln6-Trp7-Phe8-Gly9-Leu10-Met11-) (2) are NK-2 antagonists in the hamster trachea assay, whereas cyclo-(-Gln6-Trp7-Phe8-(R)-Gly9-[ANC-2]Leu10-Met11+ ++-) (3), where Gly9[ANC-2]Leu10 represents (2S)-2-((3R)-3-amino-2-oxo-1-pyrrolidinyl)-4-methylpentanoyl, is inactive as agonist and antagonist in this assay. In DMSO, the NMR results cannot be interpreted as being consistent with a single conformation. However, the combined interpretation of results from NMR spectroscopy, restrained molecular dynamics simulations with application of proton-proton distance information from ROESY spectra, and pharmacological results leads to a reduced number of conformational domains for each peptide, which can be compared with each other and may be classified as responsible for their biological activity. Trying to match the conformational domains approximately with regular beta- and gamma-turns, we find a gamma n-turn at the position of the methionine occurring in all peptides. For the active peptides 1 and 2 we arrive at an inverse gamma i-turn at Phe8, and beta I'- or beta II-turns with Gly9 and Leu10 at the corner positions, these beta-turns having a similar topology with respect to the linking peptide unit. Other conformational domains common to only 1 and 2 support their classification as responsible for the biological activity. |
| Databáze: | OpenAIRE |
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