Gordon E A, Krstenansky J L, Fishman P H
Membrane Biochemistry Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892.
Neurosci Lett. 1990 Nov 13;119(2):187-90. doi: 10.1016/0304-3940(90)90830-3.
The similarity of neuropeptide Y (NPY) to pancreatic polypeptide (PP), whose X-ray crystallographic structure is known, has allowed computer-assisted molecular modelling of NPY and predictions of its three-dimensional structure. Utilizing these techniques, Krstenansky et al. (Proc. Natl. Acad. Sci. U.S.A., 86 (1989) 4377-4381) reported that a centrally truncated analog of porcine NPY, [D-Cys7-Aoc8-17-Cys20]pNPY, which was designed to maintain the tertiary structure of the native molecule, bound to sites on membranes from mouse brain with even higher affinity than native NPY. As brain membranes may represent a heterogeneous mixture of receptor subtypes, we decided to characterize the activity of this analog on a defined cell line. SK-N-MC cells are a human epithelioma cell line with high-affinity receptors of the Y1 subtype which are coupled to inhibition of adenylate cyclase. (D-Cys7-Aoc8-17-Cys20]pNPY bound to receptors on SK-N-MC cells, but in contrast to membranes from mouse brain, with a lower affinity than pNPY. Furthermore, [D-Cys7-Aoc8-17-Cys20]pNPY was able to inhibit isoproterenol-stimulated cAMP production in these cells. Therefore, it appears that the central amino acids deleted from this analog are not involved in NPY binding, and biological activity can be maintained by conservation of the tertiary structure of NPY around the binding surface.
神经肽Y（NPY）与已知X射线晶体结构的胰多肽（PP）相似，这使得对NPY进行计算机辅助分子建模并预测其三维结构成为可能。利用这些技术，克尔斯滕anski等人（《美国国家科学院院刊》，86（1989）4377 - 4381）报告称，猪NPY的一种中央截短类似物，[D - Cys7 - Aoc8 - 17 - Cys20]pNPY，其设计目的是维持天然分子的三级结构，它与小鼠脑膜上的位点结合，亲和力甚至比天然NPY更高。由于脑膜可能代表受体亚型的异质混合物，我们决定在一种确定的细胞系上表征这种类似物的活性。SK - N - MC细胞是一种人上皮瘤细胞系，具有与抑制腺苷酸环化酶偶联的Y1亚型高亲和力受体。[D - Cys7 - Aoc8 - 17 - Cys20]pNPY与SK - N - MC细胞上的受体结合，但与小鼠脑膜不同的是，其亲和力低于pNPY。此外，[D - Cys7 - Aoc8 - 17 - Cys20]pNPY能够抑制这些细胞中异丙肾上腺素刺激的cAMP生成。因此，看起来从这种类似物中缺失的中央氨基酸不参与NPY的结合，并且通过保留结合表面周围NPY的三级结构可以维持生物活性。
