Filtz T M, Chumpradit S, Kung H F, Molinoff P B
Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia 19104.
Bioconjug Chem. 1990 Nov-Dec;1(6):394-9. doi: 10.1021/bc00006a005.
SCH-23390 is a high-affinity antagonist selective for D1 dopamine receptors (Ki = 2.5 nM). It does not contain a functional group that can be conveniently coupled to commercially available resins for affinity chromatography or to prepare photolabels for photoaffinity labeling of receptors. To construct an affinity resin for purification of dopamine D1 receptors, an aldehyde analogue of SCH-23390, (+/-)-7-chloro-8-hydroxy-1-(4'-formylphenyl)-3-methyl-2,3,4,5-tetrahydro -1H- 3-benzazepine (ASCH), was synthesized. 8-Methoxy-1-(4'-bromophenyl)-SCH-23390 was lithiated, formylated, and O-demethylated to form the aldehyde. NMR and IR analyses were performed to characterize the product. Assays were performed with the radioligand [125I]SCH-23982 to define the biological activity of the aldehyde. ASCH displaced [125I]SCH-23982 binding from caudate membranes with a Ki value of 7.1 nM. ASCH has been coupled through the aldehyde group on the phenyl ring to diaminodipropylamine-agarose for affinity chromatography. After solubilization of caudate membranes in 1% digitonin, the affinity resin retained binding sites for [125I]SCH-23982 that were eluted with 10 mM SCH-23390. The aldehyde was also covalently coupled to biotin hydrazide for fluorescence labeling of dopamine D1 receptors. The biotin-conjugated aldehyde of SCH-23390 displaced [125I]SCH-23982 binding from caudate membranes with a Ki value of 9.3 nM.
SCH - 23390是一种对D1多巴胺受体具有高亲和力的拮抗剂（Ki = 2.5 nM）。它不含有可方便地与市售树脂偶联用于亲和色谱或制备用于受体光亲和标记的光标记的官能团。为构建用于纯化多巴胺D1受体的亲和树脂，合成了SCH - 23390的醛类似物，（±）-7 - 氯 - 8 - 羟基 - 1 - （4'-甲酰基苯基）-3 - 甲基 - 2,3,4,5 - 四氢 - 1H - 3 - 苯并氮杂卓（ASCH）。将8 - 甲氧基 - 1 - （4'-溴苯基）-SCH - 23390锂化、甲酰化并进行O - 去甲基化以形成醛。进行NMR和IR分析以表征产物。用放射性配体[125I]SCH - 23982进行测定以确定醛的生物活性。ASCH以7.1 nM的Ki值从尾状核膜置换[125I]SCH - 23982结合。ASCH已通过苯环上的醛基与二氨基二丙胺 - 琼脂糖偶联用于亲和色谱。在将尾状核膜溶解于1%的洋地黄皂苷后，亲和树脂保留了[125I]SCH - 23982的结合位点，该位点用10 mM SCH - 23390洗脱。醛还与生物素酰肼共价偶联用于多巴胺D1受体的荧光标记。SCH - 23390的生物素共轭醛以9.3 nM的Ki值从尾状核膜置换[125I]SCH - 23982结合。
