Structure-activity relationships for substrates and inhibitors of pineal 5-hydroxytryptamine-N-acetyltransferase: preliminary studies
作者:Shuren Shen、Béatrice Brémont、Isabelle Serraz、Jean Andrieux、Annie Poncet、Monique Mathé-Allainmat、Evelyne Chanut、Jean-Hugues Trouvin、Michel Langlois
DOI:10.1016/0014-2999(96)00228-2
日期:1996.6
derivatives and no clear structure-activity relationship was observed. Melatonin and several bioisosteric derivatives were shown to be inhibitors of 5-HT-N-acetyltransferase. Preliminary data suggested that over the 5-50-microM concentration range, melatonin was a competitive inhibitor (IC50 = 10 microM) with a concentration-dependent inhibitory effect on its own synthesis in the pineal gland. However, the
色胺,(1-萘基)乙胺和苯乙胺衍生物作为绵羊松果体5-羟色胺-N-乙酰基转移酶(5-HT-NAT)的底物进行了测试,后者是褪黑素合成的关键酶。几乎所有的吲哚衍生物都具有与色胺类似的亲和力(Km = 0.05 mM),而取代的萘和苯基衍生物的效价较低。但是,Km值似乎受取代基的位阻和极性性质影响。萘和苯基衍生物的Vmax值通常比吲哚衍生物的Vmax值高10-20倍,并且未观察到明确的结构活性关系。褪黑激素和几种生物等位衍生物被证明是5-HT-N-乙酰基转移酶的抑制剂。初步数据表明,在5-50 microM的浓度范围内,褪黑激素是一种竞争性抑制剂(IC50 = 10 microM),对松果体自身的合成具有浓度依赖性的抑制作用。然而,生物等位萘衍生物被表征为混合抑制剂。公认的褪黑素能拮抗剂(1-萘基)乙基乙酰氨基也被证明是5-HT-N-乙酰基转移酶的抑制剂(IC50 = 8 microM),是调