NMR structure of neuromedin C, a neurotransmitter with an amino terminal CuII-, NiII-binding (ATCUN) motif.
The structure of neuromedin C, a 10-residue bombesin-like neuropeptide with the sequence Gly-Asn-His-Trp-Ala-Val-Gly-His-Leu-Met-NH2, has been investigated. Like human serum albumin, neuromedin C contains the amino-terminal CuII-, NiII-binding (ATCUN) motif which has high affinity for CuII and NiII. The solution structure of the NiII-peptide complex has been calculated based on 2D ROESY data obtained at 25 degrees C, using a hybrid distance geometry-simulated annealing approach. Comparison of 1H, 13C and 15N chemical shifts and ROESY data in the presence and absence of NiII demonstrates that the metal binds at the N-terminus of the peptide, leading to a conformational change. The metal complex adopts a conformation comprising two connected turns including residues 1Gly to 3His and 5Ala to 8His. The first turn corresponds to the NiII coordination ligands in a square planar conformation, and the second reflects the interaction between 4Trp and 8His. The results may have important physiological implications in the phenomenon of neurotransmission.
Gasmi
G
G
Department of Biochemistry Research, Hospital for Sick Children, Toronto, Ontario, Canada.
Singer
A
A
Forman-Kay
J
J
Sarkar
B
B
D000595:Amino Acid Sequence; D001839:Bombesin / Q000737:chemistry* / Q000378:metabolism; D003300:Copper / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D018377:Neurotransmitter Agents / Q000737:chemistry / Q000378:metabolism; D009532:Nickel / Q000378:metabolism*; D010446:Peptide Fragments / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation
D018377:Neurotransmitter Agents; D010446:Peptide Fragments; D003300:Copper; D009532:Nickel; C040794:neuromedin C; D001839:Bombesin