PHOTOINDUCED DNA-PROTEIN CROSS-LINKING IN CHROMATIN

由紫外线（UV）引起的细胞DNA辐射损伤 光，有许多组成过程。 其中之一是 染色体蛋白质与DNA的交联。 本 建议强调了紫外线辐射损害的这一方面， 真核染色质 我们研究的长期目标 这一领域的计划是阐明核的化学性质， 酸-蛋白质光交联，并定量评估 单个核碱基-氨基酸混合产物的重要性， 作为紫外线剂量的函数， 真核细胞染色质中的DNA。 目前的研究计划， 具体目标，试图回答以下问题： 核碱基和氨基酸参与光交联 染色体中的组蛋白到DNA（染色体的基本结构之一） 真核细胞染色质单位）？ 量化收益率是多少， 作为紫外线剂量的函数， 作为光交联的重要贡献者？ 的 以下方法将用于回答这些问题。 一组 碱基-氨基酸（或核苷-氨基酸）混合 产品将通过涉及以下反应的路线制备： 具有氨基酸或适当氨基的核碱基或核苷 酸衍生物 由此产生的混合产品将是 其特征在于它们的化学、色谱和 光谱性质 利用这些信息，他们将 在紫外线照射的染色体的水解产物中寻找。 混合产品的定量将通过使用 光交联的化学衍生的水解物 染色质体，结合高效液相色谱 色谱法和已知的化学衍生标准品 混合产品浓度。

Radiation damage to cellular DNA, caused by ultraviolet (UV) light, has a number of component processes. One of these is cross-linking of chromosomal proteins to DNA. The present proposal emphasizes this aspect of UV radiation damage to eukaryotic chromatin. The long term objective of our research program in this area is to elucidate the chemical nature of nucleic acid-protein photocross-linking and to assess quantitatively the importance of individual nucleobase-amino acid mixed products, as a function of UV dose, to the total cross-linking of proteins of DNA in eukaryotic chromatin. The present research proposal has specific goals of trying to answer the following questions: which nucleobases and amino acids participate in the photocross-linking of histones to DNA in chromatosomes (one of the basic structural units of eukaryotic chromatin)? What are the quantitative yields, as a function of UV dose, of those mixed products that are important as contributors to the photocross-linking? The following approach will be used to answer these questions. A set of nucleobase-amino acid (or nucleoside-amino acid) mixed products will be prepared by routes involving reaction of the nucleobase or nucleoside with amino acid or appropriate amino acid derivative. The resulting mixed products will be characterized as to their chemical, chromatographic and spectroscopic properties. Using this information, they will be sought in hydrosylates of UV-irradiated chromatosomes. Quantitation of mixed products will be done through the use of chemically derivatized hydrosylates of photocross-linked chromatosomes, in conjunction with high performance liquid chromatography and chemically derivatized standards of known mixed product concentration.