1n6t
Solution Structure of the Tachykinin Peptide Neurokinin ASolution Structure of the Tachykinin Peptide Neurokinin A
Structural highlights
Function[TKNB_CHICK] Tachykinins are active peptides which excite neurons, evoke behavioral responses, are potent vasodilators and secretagogues, and contract (directly or indirectly) many smooth muscles. Publication Abstract from PubMedThe solution structure of NKA, a decapeptide of mammalian origin, has been characterized by CD spectropolarimetry and 2D proton nuclear magnetic resonance (2D 1H-NMR) spectroscopy in both aqueous and membrane mimetic solvents. Unambiguous NMR assignments of protons have been made with the aid of correlation spectroscopy (DQF-COSY and TOCSY) experiments and nuclear Overhauser effect spectroscopy (NOESY and ROESY) experiments. The distance constraints obtained from the NMR data have been utilized to generate a family of structures, which have been refined using restrained energy minimization and dynamics. These data show that in water NKA prefers to be in an extended chain conformation whereas a helical conformation is induced in the central core and the C-terminal region (D4-M10) of the peptide in the presence of perdeuterated dodecylphosphocholine (DPC) micelles, a membrane model system. Though less defined the N-terminus also displays some degree of order and a possible turn structure. The conformation adopted by NKA in the presence of DPC micelles represents a structural motif typical of neurokinin-2 selective agonists and is similar to that reported for eledoisin in hydrophobic environment. Three-dimensional structure of the mammalian tachykinin peptide neurokinin A bound to lipid micelles.,Chandrashekar IR, Cowsik SM Biophys J. 2003 Dec;85(6):4002-11. PMID:14645089[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References |
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