Structures of neuropeptide γ from goldfish and mammalian neuropeptide γ, as determined by 1H NMR spectroscopy

• Published in: The journal of peptide research 2003-05, Vol.61 (5), p.274-285
• Main Authors: Lee, K., Lee, S., Kim, Y., Park, N.G.
• Format: Article
• Language: English
• Subjects: Animals; Circular Dichroism; Goldfish; Guinea Pigs; Micelles; neuro peptideγ; neurokinin A; nuclear magnetic resonance; Nuclear Magnetic Resonance, Biomolecular; Peptide Fragments - chemistry; Protein Structure, Secondary; Sodium Dodecyl Sulfate - pharmacology; Solutions; substance P; Tachykinins - chemistry; tertiary structure
• ISSN: 1397-002X; 1399-3011
• DOI: 10.1034/j.1399-3011.2003.00058.x

: Neuropeptide γ belongs to tachykinin families which have a common C‐terminal amino acid sequence (Phe‐X‐Leu‐Met‐NH2) and which induce various biological responses including salivation, hypotension, and contraction of gastrointestinal, respiratory, and urinary smooth muscle. In the present study, we present the solution structures of neuropeptide γ (NPγ) from gold fish (G‐NPγ) and mammalian NPγ (M‐NPγ), as determined by nuclear magnetic resonance (NMR) spectroscopy in 50% trifluoroethanol (TFE)/water (1 : 1, v/v) solution and 200 mm sodium dodecyl sulfate (SDS) micelles. In aqueous TFE solution, G‐NPγ has a α‐helical conformation in the region of His12–Met21 and a short helix in the N‐terminal region, and has a β‐turn from Arg9 to Arg11 in between. In aqueous TFE solution, M‐NPγ also has α‐helical conformations both in the C‐terminal region and the N‐terminal region and a β‐turn from His9 to Arg11 in between. In SDS micelle, the structure of G‐NPγ contains a stable α‐helix from His12 to Met21 and a β‐turn from Arg9 to Arg11, while M‐NPγ has a short helix from Ser16 to Met21. The region from His12 to Met21 corresponds to the amino acid sequence of neurokinin A. Neuropeptide γ may act as a precursor of neurokinin A and the post‐translational processing of this peptide involves the enzymatic attack of the basic β‐turn region from residue 9 to residue 11 in the middle. From our relaxation study, it could be suggested that in fish system G‐NPγ induces the biological actions corresponding to those of substance P in mammalian system. The structures of G‐NPγ and M‐NPγ contain α‐helical structures at the C‐terminus and this helix seems to promote the affinity for NK1 and/or NK2 receptor.