We have used combinatorial chemistry with amino acid mixtures (X) at positions 6 to 23 in vasoactive intestinal peptide (VIP) to optimize binding affinity and selectivity to the rat VPAC(1) receptor. The most efficient amino acid replacement was a substitution of alanine at position 18 to diphenylalanine (Dip), increasing the displacement efficiency of (125)I-VIP by 370-fold. The [Dip(18)]VIP(6-23) was subsequently used to find a second replacement, employing the same approach. Tyrosine at position 9 was selected and the resulting [Tyr(9),Dip(18)]VIP(6-23) analog has a K(i) value of 90 nM. This analog was unable to stimulate cAMP production at 10(-6) M but was able to inhibit VIP-induced cAMP stimulation (K(b) = 79 nM). The K(i) values of [Tyr(9),Dip(18)]VIP(6-23) using the rat VPAC(2) and PAC(1) receptors were 3,000 nM and >10,000 nM, respectively. Thus, [Tyr(9),Dip(18)]VIP(6-23) is a selective VPAC(1) receptor antagonist. The C-terminally extended form, [Tyr(9),Dip(18)]VIP(6-28), displays improved antagonistic properties having a K(i) and K(b) values of 18 nM and 16 nM, respectively. On the contrary, the fully extended form, [Tyr(9),Dip(18)]VIP(1-28), was a potent agonist with improved binding affinity (K(i) = 0.11 nM) and ability to stimulate cAMP (EC(50) = 0.23 nM) compared with VIP (K(i) = 1.7 nM, EC(50) = 1.12 nM). Furthermore, the specificity of this agonist to the VPAC(1) receptor was high, the K(i) values for the VPAC(2) and PAC(1) receptors were 53 nM and 3,100 nM, respectively. Seven other analogs with the [Tyr(9),Dip(18)] replacement combined with previously published VIP modifications have been synthesized and described in this work.

译文

:我们已将组合化学与血管活性肠肽(VIP)中6至23位的氨基酸混合物(X)结合使用,以优化与大鼠VPAC(1)受体的结合亲和力和选择性。最有效的氨基酸替换是将18位丙氨酸替换为二苯丙氨酸(Dip),使(125)I-VIP的置换效率提高370倍。随后,使用相同的方法使用[Dip(18)] VIP(6-23)查找第二个替换项。选择第9位的酪氨酸,所得的[Tyr(9),Dip(18)] VIP(6-23)类似物的K(i)值为90 nM。该类似物无法在10(-6)M刺激cAMP产生,但能够抑制VIP诱导的cAMP刺激(K(b)= 79 nM)。使用大鼠VPAC(2)和PAC(1)受体的[Tyr(9),Dip(18)] VIP(6-23)的K(i)值分别为3,000 nM和> 10,000 nM。因此,[Tyr(9),Dip(18)] VIP(6-23)是选择性的VPAC(1)受体拮抗剂。 C末端扩展形式[Tyr(9),Dip(18)] VIP(6-28)显示出改善的拮抗特性,其K(i)和K(b)值分别为18 nM和16 nM。相反,完全延伸的形式[Tyr(9),Dip(18)] VIP(1-28)是一种有效的激动剂,具有改善的结合亲和力(K(i)= 0.11 nM)和刺激cAMP的能力( EC(50)= 0.23 nM),而VIP(K(i)= 1.7 nM,EC(50)= 1.12 nM)。此外,该激动剂对VPAC(1)受体的特异性很高,VPAC(2)和PAC(1)受体的K(i)值分别为53 nM和3,100 nM。在这项工作中,已经合成并描述了七个其他具有[Tyr(9),Dip(18)]替代物并结合了先前发布的VIP修饰的类似物。

+1
+2
100研值 100研值 ¥99课程
检索文献一次
下载文献一次

去下载>

成功解锁2个技能,为你点赞

《SCI写作十大必备语法》
解决你的SCI语法难题!

技能熟练度+1

视频课《玩转文献检索》
让你成为检索达人!

恭喜完成新手挑战

手机微信扫一扫,添加好友领取

免费领《Endnote文献管理工具+教程》

微信扫码, 免费领取

手机登录

获取验证码
登录