In Vivo Screening of Mixture-Based Combinatorial Libraries

基于混合物的组合文库的体内筛选

基本信息

批准号：
7477311
负责人：
Richard Allen Houghten
金额：
$ 26.75万
依托单位：
TORREY PINES INST FOR MOLECULAR STUDIES
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-08-01 至 2010-07-31
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): Our working hypothesis is that the direct in vivo screening and identification of individual compounds from mixture-based combinatorial libraries will yield more "advanced" therapeutic candidates, while decreasing the time and costs inherent in the drug discovery process. Current drug discovery screening strategies virtually always involve target based in vitro biochemical or cell-based assays. These serve as the primary means to identify active compounds that are next assessed for their activity in animals studies. It is at this later stage that the majority of compounds fail due to toxicity, lack of efficacy, and poor bioavailability. In support of our working hypothesis, successful preliminary studies utilizing the murine tail flick pain model have demonstrated that clear differentiation can be achieved between active and inactive mixtures. For example, a mixture of 125,000 tetrapeptides, made up of 50 different amino acids at three positions and with only its N-terminal position individually defined, was found to have antinociceptive activity in the tail flick assay. The activity of this mixture (that contained Dmt-DALDA; known to be active in vivo) had a 5 to 10 time longer duration of action than morphine, while being only 3-5 times less active than morphine on a per mg basis. Additionally, other mixtures chosen that had no activity in the mu, delta or kappa opioid binding assays were found that had clear in vivo tail flick activity. This raises the exciting possibility that novel receptor sites or multiple receptor interactions are responsible for the activities found. The two Aims in this proposal will serve as a general proof of concept for this approach and will lay the foundation for later studies with a range of existing heterocyclic mixture-based libraries. The first Aim will use the tail flick assay to complete an iterative deconvolution process to identify the most active amino acids at the three positions of this active mixture. We believe that this will enable the identification of active individual sequences that have enhanced activity relative to Dmt-DALDA or, as a minimum, will identify Dmt-DALDA (both are acceptable proof of concept end results). The second Aim involves the in vivo screening of the entire 50 mixtures making up this tetrapeptide library of 6,250,000 different sequences (50 x 503). In addition to identifying novel opioid specific agonists, this approach may enable the identification of novel antinociceptive compounds that have activity at "orphan" pain modulating non-opioid receptors. If successful, the direct in vivo testing of mixture-based combinatorial libraries will advance not only pain modulation, but biomedical research and the drug discovery process in general.

描述（由申请人提供）：我们的工作假设是，基于混合物的组合库中的直接体内筛查和鉴定各个化合物将产生更多的“先进”治疗候选者，同时减少药物发现过程中固有的时间和成本。当前的药物发现筛查策略几乎始终涉及基于靶标的体外生化或基于细胞的测定法。这些是识别其在动物研究中的活性的主要手段。正是在此阶段，大多数化合物由于毒性，缺乏疗效和生物利用度差而失败。为了支持我们的工作假设，利用鼠尾动疼痛模型的成功初步研究表明，可以在主动混合物和非活动混合物之间实现明显的分化。例如，发现在三个位置由50个不同氨基酸组成的125,000个四肽的混合物，并且只有其N末端位置单独定义，在尾部轻弹测定中具有抗伤害感受活性。该混合物的活性（包含DMT-DALDA；已知在体内活性）的作用持续时间比吗啡长5至10次，而在每毫克的基础上，其活性仅比吗啡少3-5倍。此外，发现在MU，Delta或Kappa阿片类结合测定中选择的其他混合物被发现具有清晰的体内尾部弹性活性。这增加了令人兴奋的可能性，即新型受体部位或多个受体相互作用是为了发现的活动。该提案中的两个目标将成为这种方法的一般概念验证，并将为以后的一系列现有杂环混合物库奠定基础。第一个目标将使用尾部轻弹测定完成迭代反卷积过程，以鉴定该活性混合物的三个位置最活跃的氨基酸。我们认为，这将使相对于DMT-DALDA具有增强活动的主动序列的识别，或者至少将识别DMT-DALDA（两者都是概念最终结果的可接受证明）。第二个目的涉及对整个50种混合物的体内筛选，该混合物构成了该四肽库，该肽库为6,250,000个不同的序列（50 x 503）。除了鉴定新的阿片类药物特异性激动剂外，这种方法还可以鉴定出具有调节非阿片类受体的“孤儿”疼痛活性的新型抗伤害感受化合物。如果成功，基于混合物的组合文库的直接体内测试不仅会调节疼痛调节，还可以提高生物医学研究和一般药物发现过程。