SPECTROSCOPY OF HEAVY ATOM-PERTURBED BIOPOLYMERS

该研究项目的长期目标是获得 在分子水平上提供关于蛋白质-核酸相互作用的信息。 特别重要的是，我们要进一步了解 影响核酸序列选择性，以及 特殊的复合物。蛋白质和核酸之间的相互作用是 是细胞过程的基本组成部分， 用于感染因子如哺乳动物的组装和功能 逆转录病毒拟议研究的主要具体目标是研究 1型人的核衣壳蛋白的核酸复合物 免疫缺陷病毒（导致AIDS的传染因子），HIV-1 NC p7， 和猴免疫缺陷病毒SIV NC p8。沿着所有已知的 逆转录病毒NC蛋白p7和p8含有锌指CCHC阵列， 包括高度保守的芳香族残基，例如Trp和Phe。这些Zn 指状阵列与特异性核酸结合有关， 包装.我们的研究将集中在使用光学检测 p7和p8复合物的三重态磁共振（ODMR） 原子衍生化的核酸，以确定芳香堆积是否 相互作用涉及绑定。三重态零场 通过与各种不同的金属离子形成复合物， 核酸将用于定量评价 芳族堆积相互作用，以复杂的稳定性，从而，他们的 影响序列选择性。这一目标还需要进一步的努力 棘霉素（DNA双嵌入抗生素）类似物的研究 通过ODMR光谱作为堆叠诱导的序列选择性的模型。 在相关的工作中，序列特异性DNA结合蛋白，E。 coli trp阻遏物、lac阻遏物和EcoRI甲基转移酶与2- 将研究含硫尿嘧啶或2-硫代胸腺嘧啶的低聚物。 三重态-三重态能量从硫衍生的DNA碱基转移到 将利用蛋白质色氨酸残基来获得结构信息。 将广泛使用突变的蛋白质和酶， 用其它氨基酸保守取代内在色氨酸残基 作为解释光谱结果的辅助手段。任何信息 我们可以提供的与序列选择性的起源有关的信息， 尤其是七主席和八主席，将在这些领域产生重要影响 作为新型艾滋病毒抗病毒药物的设计。

The broad long term objectives of this research project are to obtain information at the molecular level about protein-nucleic acid interaction. Of particular importance is the furthering of our understanding of factors influencing nucleic acid sequence-selectivity, and the stability of specific complexes. The interaction between proteins and nucleic acids is a fundamental component of cellular processes, as well as being essential for the assembly and functioning of infectious agents such as mammalian retroviruses. The major specific aim of the proposed research is the study of nucleic acid complexes of the nucleocapsid proteins of type 1 human immunodeficiency virus (an infectious agent leading to AIDS), HIV-1 NC p7, and of simian immunodeficiency virus, SIV NC p8. Along with all known retroviral NC proteins, p7 and p8 contain zinc finger CCHC arrays that include highly conserved aromatic residues such as trp and phe. These Zn finger arrays have been implicated in specific nucleic acid binding and packaging. Our research will focus on the use of optical detection of triplet state magnetic resonance (ODMR) of p7 and p8 complexes with heavy atom-derivatized nucleic acids to determine whether aromatic stacking interactions are involved in binding. The triplet state zero-field splitting shifts induced in trp by complex formation with a variety of nucleic acids will be used to quantitatively evaluate the contribution of aromatic stacking interactions to complex stability, and thereby, their influence on sequence selectivity. This goal will require further investigations of echinomycin (a DNA bis-intercalating antibiotic) analogs by ODMR spectroscopy as models of stacking-induced sequence selectivity. In related work, complexes of sequence-specific DNA binding proteins, E. coli trp repressor, lac repressor and Eco RI methyl transferase with 2- thiouracil- or 2-thiothymine-containing oligomers will be studied. Triplet-triplet energy transfer from the sulfur-derivatized base of DNA to protein trp residues will be utilized to obtain structural information. Extensive use will be made of mutated proteins and enzymes that involve conservative substitution of intrinsic trp residues by other amino acids as an aid in interpretation of the spectroscopic results. Any information that we can provide that bears on the origins of sequence selectivity of p7 and p8, in particular, would have important implications in such areas as the design of novel HIV antiviral agents.