Multiple forms of nuclear deoxyribonuclease in rat thymocytes.
Multiple forms of nuclear deoxyribonuclease in rat thymocytes.
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大鼠胸腺细胞中多种形式的核脱氧核糖核酸酶。
DOI：
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
D. Shiokawa
中科院分区：
文献类型：
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作者：
S. Tanuma;D. Shiokawa
从大鼠胸腺细胞核中分离出三种不同的核酸内切酶（DNA酶α、β和γ）。这三种DNA酶在色谱行为和表观分子量上不同。酸性DNA酶α和β的同源形式不需要二价阳离子来进行其活性，而DNA酶γ是中性内切核酸酶，其需要Ca 2+和Mg 2+来进行完全活性，并且被Zn 2+抑制。这些酶将HeLa S3细胞核染色质消化成具有凋亡特征的核小体片段。有趣的是，由γ射线照射或糖皮质激素诱导的大鼠胸腺细胞核凋亡保留了相当大的DNase γ活性，而DNase α和β的活性显着降低。这些结果表明，在大鼠胸腺细胞DNA酶γ参与细胞凋亡过程中的DNA片段化。
Three distinct endonucleases (DNase alpha, beta and gamma) were isolated from rat thymocyte nuclei. These three DNases differed in chromatographic behaviors and in apparent molecular masses. The cognate form of acidic DNases alpha and beta did not require divalent cations for their activities, whereas DNase gamma was a neutral endonuclease that required both Ca2+ and Mg2+ for full activity and was inhibited by Zn2+. These enzymes digested HeLa S3 cell nuclear chromatin to the nucleosomal fragments characteristic of apoptosis. Interestingly, apoptotic rat thymocyte nuclei induced by gamma-ray irradiation or glucocorticoid retained considerable activity of DNase gamma, whereas their activities of DNases alpha and beta were markedly reduced. These results indicate that in rat thymocytes DNase gamma is involved in DNA fragmentation during apoptosis.