Excision of X-ray-induced thymine damage in chromatin from heated cells.
Excision of X-ray-induced thymine damage in chromatin from heated cells.
复制标题
从加热的细胞中切除 X 射线诱导的染色质胸腺嘧啶损伤。
作者：
R. Warters;J. L. Roti
通过实验来区分两种可能的高温诱导抑制CHO细胞DNA胸腺嘧啶碱基损伤切除的模式：(1)切除酶的热变性(s)或(2)热诱导底物的损伤切除（染色质）改变。虽然高温（45/sup 0/C， 15分钟）对切除酶去除DNA损伤的能力没有明显影响，但对染色质作为未加热酶的底物的能力有显著影响（约80%的抑制）。这些结果表明，高热诱导的CHO细胞的放射致敏可能主要是由于细胞染色质的损伤。
Experiments were performed to distinguish between two possible modes of hyperthermia-induced inhibition of thymine base damage excision from the DNA of CHO cells: (1) heat denaturation of excision enzyme(s) or (2) heat-induced alteration of the substrate for damage excision (chromatin). While hyperthermia (45/sup 0/C, 15 min) had no apparent effect on the capacity of the excision enzymes to excise damage from DNA it had a dramatic effect (ca. 80% inhibition) on the ability of chromatin to serve as a substrate for unheated enzymes. These results suggest that hyperthermia-induced radiosensitization of CHO cells may be due primarily to lesions in the cellular chromatin.