Mimicking the membrane-mediated conformation of dynorphin A-(1-13)-peptide: Circular dichroism and nuclear magnetic resonance studies in methanolic solution
- McMaster Univ., Hamilton, Ontario (Canada)
- Carnegie-Mellon Univ., Pittsburgh, PA (USA)
- Univ. Hospital Centre, Sherbrooke, Quebec (Canada)
The structural requirements for the binding of dynorphin to the {kappa}-opioid receptor are of profound clinical interest in the search for a powerful nonaddictive analgesic. These requirements are thought to be met by the membrane-mediated conformation of the opioid peptide dynorphin A-(1-13)-peptide, Tyr{sup 1}-Gly{sup 2}-Gly{sup 3}-Phe{sup 4}-Leu{sup 5}-Arg{sup 6}-Arg{sup 7}-Ile{sup 8}-Arg{sup 9}-Pro{sup 10}-Lys{sup 11}-Leu{sup 12}-Lys{sup 13}. Schwyzer has proposed an essentially {alpha}-helical membrane-mediated conformation of the 13 amino acid peptide. In the present study, circular dichroism (CD) studies on dynorphin A-(1-13)-peptide bound to an anionic phospholipid signified negligible helical content of the peptide. CD studies also demonstrated that the aqueous-membraneous interphase may be mimicked by methanol. The 500- and 620-MHz {sup 1}H nuclear magnetic resonance (NMR) spectra of dynorphin A-(1-13)-peptide in methanolic solution were sequence-specifically assigned with the aid of correlated spectroscopy (COSY), double-quantum filtered phase-sensitive COSY (DQF-COSY), relayed COSY (RELAY), and nuclear Overhauser enhancement spectroscopy (NOESY). 2-D CAMELSPIN/ROESY experiments indicated that at least the part of the molecule from Arg{sup 7} to Arg{sup 9} was in an extended or {beta}-strand conformation, which agreed with deuterium-exchange and temperature-dependence studies of the amide protons and analysis of the vicinal spin-spin coupling constants {sup 3}J{sub HN{alpha}}. The results clearly demonstrated the absence of extensive {alpha}-helix formation. {chi}{sub 1} rotamer analysis of the {sup 3}J{sub {alpha}{beta}} demonstrated no preferred side-chain conformations.
- OSTI ID:
- 5464190
- Journal Information:
- Biochemistry; (United States), Vol. 30:19; ISSN 0006-2960
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ANALGESICS
MOLECULAR STRUCTURE
MEMBRANE PROTEINS
STRUCTURE-ACTIVITY RELATIONSHIPS
CONFORMATIONAL CHANGES
MAGNETIC CIRCULAR DICHROISM
NUCLEAR MAGNETIC RESONANCE
PROTEIN ENGINEERING
TEMPERATURE DEPENDENCE
CENTRAL NERVOUS SYSTEM DEPRESSANTS
DICHROISM
DRUGS
MAGNETIC RESONANCE
ORGANIC COMPOUNDS
PROTEINS
RESONANCE
550201* - Biochemistry- Tracer Techniques