Elucidation of the vasoactive intestinal peptide pharmacophore for VPAC2 receptors in human and rat and comparison to the pharmacophore for VPAC1 receptors
Elucidation of the vasoactive intestinal peptide pharmacophore for VPAC2 receptors in human and rat and comparison to the pharmacophore for VPAC1 receptors
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DOI：
10.1124/jpet.102.038075
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发表时间：
2002-11-01
影响因子：
3.5
通讯作者：
Jensen, RT
中科院分区：
文献类型：
--
作者：
Igarashi, H;Ito, T;Jensen, RT
血管活性肠肽（VIP）作为一种神经递质参与多种生理和病理状态。VIP的作用通过VPAC（1）和VPAC（2）介导。与已被广泛研究的VPAC（1）相反，对VPAC（2）的药理学知之甚少。在本研究中，我们通过丙氨酸和D-氨基酸扫描来研究VPAC（2）的VIP药效团。我们发现了显著的物种差异，并且在中国仓鼠卵巢（CHO）细胞中表达的人VPAC（2）（hVPAC（2））（已在先前的研究中使用）与Sup T-1细胞中的天然hVPAC（2）和PANC 1细胞中表达的hVPAC（2）显著不同。VPAC（2）激活的结合亲和力和效力之间存在密切的一致性。其主链或侧链取向对高亲和力效力最重要的氨基酸是Asp（3）、Phe（6）、Thr（7）、Tyr（10）、Arg（12）、Tyr（22）和Leu（23），而Ser（2）、Asp（8）、Asn（9）、Gln（16）、瓦尔（19）、Lys（20）、Lys（21）、Asn（24）、Gln（25）、Gln（26）和Leu（26）的侧链取向对高亲和力效力最重要。和Ser（25）不是必需的。hVPAC（1）和hVPAC（2）之间VIP药效团的比较表明，Thr（7）、Tyr（10）、Thr（11）和Tyr（22）的侧链对于hVPAC（2）的高亲和力比hVPAC（1）重要得多。相反，Asn（24）侧链的取向对于hVPAC（1）的高亲和力更重要。这项研究表明，在评估VPAC（2）的VIP类似物的药效团时，需要考虑重要的物种差异以及使用的表达系统。我们的研究结果应该是有用的设计VPAC亚型选择性类似物，简化的类似物，并可能代谢稳定的类似物。
Vasoactive intestinal peptide (VIP) functions as a neurotransmitter involved in a number of physiological and pathological conditions. The actions of VIP are mediated through VPAC(1) and VPAC(2). In contrast to VPAC(1), which has been extensively studied, little is known about the pharmacology of VPAC(2). In this study we investigated the VIP pharmacophore for VPAC(2) by using alanine and D-amino acid scanning. We found significant species differences, and the human VPAC(2) (hVPAC(2)) expressed in Chinese hamster ovary (CHO) cells, which have been used in previous studies, differed significantly from the native hVPAC(2) in Sup T-1 cells and hVPAC(2) expressed in PANC1 cells. There was a close agreement between binding affinities and potencies for VPAC(2) activation. The amino acids whose backbone or side chain orientations were most important for high affinity potency are Asp(3), Phe(6), Thr(7), Tyr(10), Arg(12), Tyr(22), and Leu(23), whereas the side chains of Ser(2), Asp(8), Asn(9), Gln(16), Val(19), Lys(20), Lys(21), Asn(24), and Ser(25) are not essential. Comparison of the VIP pharmacophore between hVPAC(1) and hVPAC(2) demonstrated that the side chains of Thr(7), Tyr(10), Thr(11), and Tyr(22) were much more critical for high affinity for the hVPAC(2) than the hVPAC(1). In contrast, the orientation of the side chain of Asn(24) was more important for high affinity for the hVPAC(1). This study shows that in assessing the pharmacophore of VIP analogs for the VPAC(2), important species differences need to be considered as well as the expression system used. These results of our study should be useful for designing VPAC subtype-selective analogs, simplified analogs, and possibly metabolically stable analogs.