Novel analogues of neuropeptide Y with a preference for the Y1-receptor.
Neuropeptide Y (NPY) is one of the most abundant neuropeptides in the mammalian brain and acts in humans via at least three receptor subtypes: Y1, Y2, and Y5. Whereas selective agonists and antagonists are known for the Y2- and Y5-receptors, the Y1-receptor still lacks a highly selective agonist. This work presents the first NPY-based analogues with Y1-receptor preference and agonistic properties. Furthermore, the importance of specific amino acids of NPY for binding to the Y-receptor subtypes is presented. Amongst the analogues tested, [Phe7,Pro34]pNPY (where pNPY is porcine neuropeptide Y) showed the most significant Y1-receptor preference (> 1 : 3000-fold), with subnanomolar affinity to the Y1-receptor, and Ki values of approximately 30 nM for the Y2- and Y5-subtype, respectively. Variations of position 6, especially [Arg6,Pro34]pNPY and variations within positions 20-23 of NPY were found to result in further analogues with significant Y1-receptor preference (1 : 400-1 : 2000). In contrast, cyclo S-S [Cys20,Cys24]pNPY was found to be a highly selective ligand at the Y2-receptor, binding only threefold less efficiently than NPY. Analogues containing variations of positions 31 and 32 showed highly reduced affinity to the Y1-receptor, while binding to the Y5-receptor was affected less. Inhibition of cAMP-accumulation of selected peptides with replacements within position 20-23 of NPY showed preserved agonistic properties. The NPY analogues tested give insights into ligand-receptor interaction of NPY at the Y1-, Y2- and Y5-receptor and contribute to our understanding of subtype selectivity. Furthermore, the Y1-receptor-preferring peptides are novel tools that will provide insight into the physiological role of the Y1-receptor.
Söll
R M
RM
Institute of Biochemistry, University of Leipzig, Germany.
Dinger
M C
MC
Lundell
I
I
Larhammer
D
D
Beck-Sickinger
A G
AG
D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D002645:Chickens; D002942:Circular Dichroism; D006224:Cricetinae; D000242:Cyclic AMP / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008024:Ligands; D008969:Molecular Sequence Data; D009478:Neuropeptide Y / Q000031:analogs & derivatives* / Q000737:chemistry*; D010452:Peptide Biosynthesis; D011485:Protein Binding; D011487:Protein Conformation; D017476:Receptors, Neuropeptide Y / Q000737:chemistry*; D013552:Swine; D014162:Transfection; D014407:Tumor Cells, Cultured
D008024:Ligands; D009478:Neuropeptide Y; D017476:Receptors, Neuropeptide Y; C097212:neuropeptide Y-Y1 receptor; D000242:Cyclic AMP