正常细胞和着色性干皮病细胞DNA中嘧啶二聚体的光复活作用

Photoreactivation of pyrimidine dimers in the DNA of normal and xeroderma pigmentosum cells.

作者信息

Sutherland B M, Oliver R, Fuselier C O, Sutherland J C

出版信息

Biochemistry. 1976 Jan 27;15(2):402-6. doi: 10.1021/bi00647a025.

Abstract

Photoproducts formed in the DNA of human cells irradiated with ultraviolet light (uv) were identified as cyclobuytl pyrimidine dimers by their chromatographic mobility, reversibility to monomers upon short wavelength uv irradiation, and comparison of the kinetics of this monomerization with that of authentic cis-syn thymine-thymine dimers prepared by irradiation of thymine in ice. The level of cellular photoreactivation of these dimers reflects the level of photoreactivating enzyme measured in cell extracts. Action spectra for cellular dimer photoreactivation in the xeroderma pigmentosum line XP12BE agree in range (300 nm to at least 577 nm) and maximum (near 400 nm) with that for photoreactivation by purified human photoreactivating enzyme. Normal human cells can also photoreactivate dimers in their DNA. The action spectrum for the cellular monomerization of dimers is similar to that for photoreactivation by the photoreactivating enzyme in extracts of normal human fibroblasts.

摘要

用紫外线（uv）照射人类细胞的DNA后形成的光产物，通过其色谱迁移率、短波长uv照射后向单体的可逆性，以及将这种单体化动力学与在冰中照射胸腺嘧啶制备的真实顺式-反式胸腺嘧啶-胸腺嘧啶二聚体的动力学进行比较，被鉴定为环丁烷嘧啶二聚体。这些二聚体的细胞光复活水平反映了在细胞提取物中测得的光复活酶水平。着色性干皮病细胞系XP12BE中细胞二聚体光复活的作用光谱在范围（300纳米至至少577纳米）和最大值（接近400纳米）上与纯化的人类光复活酶的光复活作用光谱一致。正常人细胞也能使其DNA中的二聚体发生光复活。二聚体细胞单体化的作用光谱与正常人成纤维细胞提取物中光复活酶的光复活作用光谱相似。