Dautzenberg Frank M, Neysari Shiva
F. Hoffmann-La Roche AG, Preclinical Research, Basel, Switzerland.
Pharmacology. 2005 Dec;75(1):21-9. doi: 10.1159/000085897. Epub 2005 May 20.
Neuropeptide Y (NPY) receptors type 1 (Y1), type 2 Y2) and type 5 (Y5) were tested for their kinetic properties to bind radiolabeled NPY or PYY. Rapid association and dissociation was observed with recombinant (HEK293 cells) and endogenous (SK-N-MC cells) human Y1 and recombinant mouse Y5 receptors. Recombinant (HEK293) and endogenous (SMS-KAN) human Y2 receptors bound both radiolabels comparable to the Y1 receptors, but only minimal ( approximately 20%) dissociation of both radiolabels was observed after long incubation time (>8 h). Furthermore, neither peptide nor small molecule Y2 ligands efficiently competed for binding to Y2 receptors once association binding had been initiated. The Y2-selective antagonist BIIE0246 behaved as an insurmountable antagonist in functional assays when pre-incubated for 30 min before agonist addition, but was a competitive antagonist when co-applied with the agonist. These data show that Y2 receptors in contrast to Y1 and Y5 receptors bind their ligands in an irreversible manner.
对1型神经肽Y（NPY）受体（Y1）、2型（Y2）和5型（Y5）进行了检测，以研究它们与放射性标记的NPY或PYY结合的动力学特性。在重组（HEK293细胞）和内源性（SK-N-MC细胞）人Y1受体以及重组小鼠Y5受体中观察到了快速结合和解离。重组（HEK293）和内源性（SMS-KAN）人Y2受体与两种放射性标记的结合情况与Y1受体相当，但在长时间孵育（>8小时）后，仅观察到两种放射性标记的极小程度（约20%）解离。此外，一旦开始结合，肽类或小分子Y2配体都不能有效地竞争与Y2受体的结合。Y2选择性拮抗剂BIIE0246在功能试验中，在加入激动剂前预孵育30分钟时表现为不可克服的拮抗剂，但与激动剂共同应用时则为竞争性拮抗剂。这些数据表明，与Y1和Y5受体相比，Y2受体以不可逆的方式结合其配体。
