PHOTOINDUCED DNA-PROTEIN CROSS-LINKING IN CHROMATIN

紫外线(UV)对细胞DNA的辐射损伤 光，有多个组成过程。其中之一是 染色体蛋白质与DNA的交联性。现在 提案强调了这方面的紫外线辐射损害 真核细胞染色质。我们研究的长期目标是 这一领域的计划是阐明原子核的化学性质 酸-蛋白质光交联和定量评估 个别核酸基-氨基酸混合产物的重要性， 作为紫外线剂量的函数，对蛋白质的总交联度 真核细胞染色质中的DNA。目前的研究提案具有 试图回答以下问题的具体目标： 碱基和氨基酸参与了光交联。 染色体中组蛋白到DNA的结合(染色体的基本结构之一 真核细胞染色质的单位)？定量收益率是多少， 作为紫外线剂量的函数，这些混合产品 作为光交联剂的重要贡献者？这个 以下方法将被用来回答这些问题。一套 碱基-氨基酸(或核苷-氨基酸)的混合物 产品将通过涉及反应的路线进行制备 含氨基酸或适当氨基酸的碱基或核苷 酸衍生物。由此产生的混合产品将是 它们的化学、层析和 光谱性质。利用这些信息，他们将被 在紫外线照射的染色体的水合物中寻找。 混合产品的量化将通过使用 光交联剂的化学衍生化水合物 染色体与高效液体联用 已知的层析和化学衍生化标准 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.