Properties of mitochondrial thymidine kinases of parental and enzyme-deficient HeLa cells.
Properties of mitochondrial thymidine kinases of parental and enzyme-deficient HeLa cells.
复制标题
亲本和酶缺陷型 HeLa 细胞线粒体胸苷激酶的特性。
DOI：
10.1016/0003-9861(73)90542-0
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发表时间：
1973
影响因子：
3.9
通讯作者：
D. Trkula
中科院分区：
文献类型：
--
作者：
S. Kit;W. Leung;D. Trkula
HeLa（BU 25）是HeLa S3细胞的突变亚系，含有线粒体胸苷（dT）激酶，尽管“细胞质”（高速上清液）细胞组分的dT激酶活性显著缺乏。HeLa（BU 25）线粒体dT激酶与亲本HeLa S3细胞的“胞质溶胶”酶在沉降系数、利用核糖核苷5′-三磷酸而非ATP作为磷酸供体的能力、对dCTP抑制的敏感性以及圆盘聚丙烯酰胺凝胶电泳（圆盘PAGE）模式方面不同。两种dT激酶活性[相对迁移率（Rm）为0.4和0.6-0.7]在HeLa（BU 25）线粒体提取物的圆盘PAGE后被检测到，并且两种活性比dT激酶阳性人类细胞的典型胞质溶胶酶（Rm = 0.2）迁移更快。HeLa（BU 25）线粒体的0.6至0.7-Rm dT激酶（但不是0.4-Rm活性）利用GTP和UTP以及ATP作为磷酸供体。HeLa S3线粒体组分含有0.6-0.7 Rm和0.4-Rm活性，此外，还有“胞质样”0.2-Rm活性。HeLa S3线粒体的0.6 - 0.7-Rm dT激酶利用UTP或ATP作为磷酸供体，但0.4-和0.2-Rm dT激酶仅利用ATP。类似地，HeLa S3细胞质dT激酶有效地利用ATP，但不是UTP，作为磷酸供体。
HeLa(BU25), a mutant subline of HeLa S3 cells, contains mitochondrial thymidine (dT) kinase, despite a marked deficiency in the dT kinase activity of the “cytosol” (high-speed supernatant) cell fraction. The HeLa(BU25) mitochondrial dT kinase differs from the “cytosol” enzyme of parental HeLa S3 cells in sedimentation coefficient, ability to utilize ribonucleoside 5′-triphosphates other than ATP as phosphate donors, sensitivity to inhibition by dCTP, and in disc polyacrylamide gel electrophoretic (disc PAGE) patterns. Two dT kinase activities [relative mobilities (Rm) of 0.4 and 0.6–0.7] were detected after disc PAGE of HeLa(BU25) mitochondrial extracts and both activities migrated more rapidly than the typical cytosol enzyme (Rm = 0.2) of dT kinase-positive human cells. The 0.6 to 0.7-Rm dT kinase of HeLa(BU25) mitochondria, but not the 0.4-Rm activity, utilized GTP and UTP, as well as ATP, as phosphate donors. HeLa S3 mitochondrial fractions contained the 0.6–0.7 Rm and the 0.4-Rm activities, and in addition, a “cytosol-like” 0.2-Rm activity. The 0.6 to 0.7-Rm dT kinase of HeLa S3 mitochondria utilized either UTP or ATP as phosphate donors, but the 0.4- and 0.2-Rm dT kinases utilized only ATP. Similarly, the HeLa S3 cytosol dT kinase efficiently utilized ATP, but not UTP, as a phosphate donor.