Söll R M, Dinger M C, Lundell I, Larhammer D, Beck-Sickinger A G
Institute of Biochemistry, University of Leipzig, Germany.
Eur J Biochem. 2001 May;268(10):2828-37. doi: 10.1046/j.1432-1327.2001.02161.x.
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.
神经肽Y（NPY）是哺乳动物大脑中含量最为丰富的神经肽之一，在人体内通过至少三种受体亚型发挥作用：Y1、Y2和Y5。虽然已知Y2和Y5受体的选择性激动剂和拮抗剂，但Y1受体仍然缺乏高选择性激动剂。这项研究展示了首个对Y1受体具有偏好性和激动特性的基于NPY的类似物。此外，还介绍了NPY特定氨基酸对与Y受体亚型结合的重要性。在所测试的类似物中，[Phe7,Pro34]pNPY（其中pNPY是猪神经肽Y）表现出最显著的Y1受体偏好性（>1:3000倍），对Y1受体具有亚纳摩尔亲和力，对Y2和Y5亚型的Ki值分别约为30 nM。发现第6位的变异，特别是[Arg6,Pro34]pNPY以及NPY第20 - 23位内的变异会产生其他对Y1受体具有显著偏好性的类似物（1:400 - 1:2000）。相比之下，环S - S [Cys20,Cys24]pNPY被发现是Y2受体的高选择性配体，其结合效率仅比NPY低三倍。含有第31和32位变异的类似物对Y1受体的亲和力大幅降低，而对Y5受体结合的影响较小。对NPY第20 - 23位进行替换的选定肽对cAMP积累的抑制作用显示出保留的激动特性。所测试的NPY类似物有助于深入了解NPY在Y1、Y2和Y5受体处的配体 - 受体相互作用，并有助于我们理解亚型选择性。此外，偏好Y1受体的肽是新型工具，将有助于深入了解Y1受体的生理作用。
