NMR STUDY OF MODIFIED DNA DUPLEXES

随着2D-NMR技术的发展，生物大分子的结构研究已成为常规。近年来，药物分子与寡核苷酸或多肽的相互作用，DNA-蛋白质相互作用揭示了精细的结构细节，说明了底物-受体结合，药物识别谱和寡核苷酸的结构异常，并强调了它们在设计有效的生物动力学试剂中的意义。对含有脱碱基位点的寡核苷酸序列的个别结构研究已经发表，但尚未完成解码脱碱基位点的侧翼碱基对DNA的整体结构的贡献的详细说明。提供这样的研究是至关重要的，它将破译含有致癌无碱基位点病变的DNA中侧翼碱基对的作用。一个完整的2D-NMR研究产生所需的结构参数的结构优化的分子动力学策略将提供这样的帐户，这将有助于设计更有效的药物治疗癌症。最近几个研究小组开发了一种全新的方法，通过设计共价连接到小沟结合药物的寡核苷酸，并估计它们与其他DNA和RNA序列的杂交能力。这种强结合的DNA缀合物具有反义试剂的潜力，其选择性地结合特定序列，从而在癌症和AIDS的管理中阻断它们的进一步复制/转录。这种方法预示着一个新的地平线，在处理突变的DNA/RNA序列，同时处理艾滋病病毒或致突变细胞的核蛋白。我们的合作者在Epoch Pharmaceuticals设计并制备了含有CDPI 3部分和两个等排鸟嘌呤ppG残基的DNA缀合物，将通过2D-NMR方法评估其结构细节。本研究将有助于开发更有效的反义/抗基因药物。与佛罗里达州奥兰多市沃尔特迪士尼纪念癌症研究所/分子分期公司的巴里施韦策博士合作，纽黑文，CT已经成立，谁将协助该提案的各个方面，特别是在结构细化协议。

With the advancement in 2D-NMR methodologies, the structural investigatiOn of biological macromolecules has become routine. In recent past, interaction of drug molecules with Oligonucleotides or polypeptides, DNA-protein interaction have revealed fine structural details that illustrate the substrate-receptor binding, drug recognition profile, and structural abnormalities of oligonucleotides, and underline their implications in the design of potent biodynamic agents. Individual structural studies on oligonucleotide sequences containing abasic sites have been published, but a detailed account decoding the contribution of flanking base pairs of an abasic site on the overall structure of a DNA has not been accomplished. It becomes essential to furnish such a study, which would decipher the role of flanking base pairs in a DNA containing a carcinogenic abasic site lesion. A complete 2D-NMR study generating structural parameters required for the structure refinement by molecular dynamics strategies would furnish such account, which will aid in designing more potent drugs in the treatment of cancers. A whole new approach has been developed recently by few research groups, by designing oligonucleotides covalently linked to a minor groove binding drug and estimating their hybridization capability with other DNA and RNA sequences. Such strongly binding DNA conjugates have a potential of antisense agents, which selectively bind to specific sequences, thus blocking their further replication/transcription in the management of cancer and AIDS. This approach is heralding a new horizon in handling the mutant DNA/RNA sequences, while dealing with nucleoproteins of AIDS virus or mutagenic cells. A DNA conjugate containing a CDPI3 moiety, and two isoteric guanine, ppG residues, has been designed and prepared by our collaborators at Epoch Pharmaceuticals, which will be evaluated by 2D-NMR methods for structural details. This study will help developing more potent antisense/antigene agents. A collaboration with Dr. Barry Schweitzer of Walt Disney Memorial Cancer Institute, Orlando, FL/Molecular Staging, Inc., New Haven, CT has been established, who will assist in various aspects of the proposal, specially in structure refinement protocols.