Abstract |
The tertiary structure of the pain modulating and anti- opiate neuropeptide, human neuropeptide AF (NPAF) (the sequence is AGEGLNSQFWSLAAPQRF-NH(2)), was determined by (1)H-NMR. The structure of NPAF was determined in two solvent systems, namely 50%/50% trifluoroethanol-d(3)/H(2)O ( TFE/H(2)O) and in the cell membrane mimetic micelle, sodium dodecylsulfate-d(25) (SDS). The receptor for NPAF is an orphan G-protein coupled receptor, and the micellar SDS solvent system was used to emulate the cell membrane surface in line with the Cell Membrane Compartments Theory proposed by R. Schwyzer ( Biopolymers, 1995, Vol. 37, pp. 5-16). In both solvent systems, NPAF was found to be primarily alpha-helical within the central portion of the molecule, from Asn(6) to Ala(14). The N-terminus was random in both solvent systems. In the SDS solution, the C-terminal tetrapeptide was structured and formed a type I beta-turn, whereas in TFE/H(2)O it was unstructured, showing the importance of the C-terminal tetrapeptide in receptor recognition. NPAF was found to associate with SDS, and was shown to be near the surface of the micelle by spin label studies with 5-doxyl-stearic acid.
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Authors | Mark Miskolzie, George Kotovych |
Journal | Biopolymers
(Biopolymers)
Vol. 69
Issue 2
Pg. 201-15
(Jun 2003)
ISSN: 0006-3525 [Print] United States |
PMID | 12767123
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Copyright | Copyright 2003 Wiley Periodicals, Inc. |
Chemical References |
- Oligopeptides
- Receptors, Neuropeptide
- Solutions
- Solvents
- Spin Labels
- Water
- Sodium Dodecyl Sulfate
- Trifluoroethanol
- A18Famide
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Topics |
- Amino Acid Sequence
- Magnetic Resonance Spectroscopy
- Models, Molecular
- Nuclear Magnetic Resonance, Biomolecular
(methods)
- Oligopeptides
(chemistry)
- Protein Conformation
- Receptors, Neuropeptide
(genetics, metabolism)
- Sodium Dodecyl Sulfate
(chemistry)
- Solutions
- Solvents
- Spin Labels
- Trifluoroethanol
(chemistry)
- Water
(chemistry)
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