Solution conformation of human neuropeptide Y by ¹H nuclear magnetic resonance and restrained molecular dynamics

Abstract

The solution structure of human neuropeptide Y has been solved by conventional two-dimensional NMR techniques followed by distance-geometry and molecular-dynamics methods. Thc conformation obtained is composed of two short contiguous ol-helices comprising residues 15 -26 and 28 -35, linked by a hinge inducing a 100' angle. l h e first helix (15-26) is connected to a polyproline stretch (residues 1 -10) by a tight hairpin (residues 11 -14). The helices and thc polyprolinc stretch are packed together by hydrophobic interactions. This structure is related to that of the homologous avian pancreatic polypeptide and bovine pancreatic polypeptide. The C-and N-terminii, known to be involved in the biological activity for respectively the receptor binding and activation, are close together in space. The side chains of residues Arg33, Arg35 and Tyr36 on the one hand, and Tyrl and Pro2 on the other, form a continuous solvent-exposed surface of 4.9 nm2 which is supposed to interact with the receptor for neuropeptide Y Neuropeptide Y (NPY) is a 36-amino-acid neurotransmitter peptide (Fig. I), first isolated from porcine brain [l], but also found throughout the central and peripheral nervous system of many mammalian species, including man [2, 31. NPY has been identified within specific peptidergic neurons of central and autonomic nervous system. In the central nervous system, NPY stimulates food intake, produces cardiovascular depression, and inhibits the release of luteinizing hormone. In the periphery, it is a potent vasoconstrictor and a presynaptic inhibitor of neurotransmission (for a review, see [4]).NPY belongs to a family of homologous peptides, which includes peptide YY and the pancreatic polypeptides [3]. A member of this family, the avian pancreatic polypeptide (APP) has been crystallized and its structure determined by X-ray diffraction [5]. More recently, the structure of bovine pancreatic polypeptidc (BPP) has been determined by two-dimensional NMK in water [6]. Both APP and BPP have a verywell-defined C-terminal a-helix, involving residues 2 5 -32. This helix and the C-terminal region are joined by a turn. The rather ordered conformation of residues 4-8 is maintained by hydrophobic interaction between the helix and the Nterminal region. Both APP and BPP share a similar conformation.Models of NPY based on the crystal structure of the APP [5, 71 have been proposed [8,9]. Previous NMR studies as well as CD analysis [lo] have demonstrated that NPY, despite its small sizc and the absence of disulfide bridge, adopted a wellordered three-dimensional structure in water. However, the structure of the NPY dimer in solution has been described [ll]. This structure is composed of a helix consisting of residues 11 ~ 36 and an unstructured mobile N-terminal segment. This structure disagrees with those of APP and BPP.In this paper, we present the three-dimensional structure of huinan NPY in water as a monomer, obtained by distance geometry, restrained energy minimization and restrained simulated annealing. This structure is c...

Cloning and characterization of hdlg: the human homologue of the Drosophila discs large tumor suppressor binds to protein 4.1.

“…Furthermore, the (PXX). spacing of proline residues is consistent with the formation of an extended polyproline II helix (29), a structure that has been shown to interact with the conserved hydrophobic groove common to the known SH3 structures (30).…”

Structure activity studies of mast cell activation and hypotension induced by neuropeptide Y (NPY), centrally truncated and C‐terminal NPY analogues

“…A 1H-NMR study on neuropeptide Y monomers in water confirmed the presence of the hairpin loop based on a series of long range nuclear Overhauser effects (NOEs) between the N-and Cterminal segments (Darbon et al, 1992). The secondary structure obtained by NMR is in agreement with the model of Allen et al (1987), as well as with the results obtained from structure activity relationships, which have suggested a close contact between the N-and C-terminal segments (Beck et al, 1989a, b;Beck-Sickinger et al, 1990a, b;1992a, b).…”

Peptide Mapping of a Novel Discontinuous Epitope of the Major Surface Adhesin from Streptococcus mutans

“…p892 and p931) are indicated by the arrows. Structural analysis of proline-rich regions in other proteins (28,29), where proline is present as every third residue, suggests that these regions adopt a conformation with 3 residues per turn, known as the polyproline II (PP II) helix, with a 3.1-Å rise/residue (30). By analogy it is predicted that the P-region of SA I/II, which also contains frequently repeating (PXX) n motifs, may also adopt a PP II helix-like conformation (31).…”