Yuyama S, Corff S C, Young P G
Department of Zoology, University of Toronto, Ontario, Canada.
Comp Biochem Physiol B. 1979;62(4):325-8. doi: 10.1016/0305-0491(79)90097-x.
Activities of typical thymidine kinase and nucleoside phosphotransferase are both present in logarithmically growing tetrahymena pyriformis, GL-1 and ST strains, contrary to previous reports. 2. Activities of thymidine kinase and nucleoside phosphotransferase are also found in both GL-1 and ST strains grown in the defined medium, PPL medium and Neff's medium. 3. The specific activities of both enzymes are very much influenced by the growth state. Both the specific activities of thymidine kinase and nucleoside phosphotransferase decrease steadily from the start of the experiments when the cell numbers were about 2-3 x 10(4) cells/ml in the PPL medium, while in the Neff's medium, the specific activities of thymidine kinase increase up to when the cell numbers reached 3-5 x 10(5) cells/ml and then decreased, but the specific activities of nucleoside phosphotransferase continuously decreased when the cell concentrations were 2-6 x 10(4) cells/ml. 4. In the PPL medium, the final cell numbers reached are about 6.5 x 10(5) cells/ml, while in the Neff's medium, the cell numbers increase further (to about 2 x 10(6) cells/ml). 5. No striking difference in activities of thymidine kinase and nucleoside phosphotransferase was observed when the cells were transferred from the defined medium to the Neff's medium, contrary to that reported by others for the activity of thymidylate synthetase.
与之前的报道相反，典型的胸苷激酶和核苷磷酸转移酶的活性在对数生长期的梨形四膜虫GL-1和ST菌株中均有存在。2. 在限定培养基PPL培养基和内夫培养基中生长的GL-1和ST菌株中也发现了胸苷激酶和核苷磷酸转移酶的活性。3. 两种酶的比活性受生长状态的影响很大。在PPL培养基中，当细胞数量约为2-3×10⁴个细胞/毫升时，从实验开始，胸苷激酶和核苷磷酸转移酶的比活性就稳步下降；而在内夫培养基中，当细胞数量达到3-5×10⁵个细胞/毫升时，胸苷激酶的比活性上升，之后下降，但当细胞浓度为2-6×10⁴个细胞/毫升时，核苷磷酸转移酶的比活性持续下降。4. 在PPL培养基中，最终达到的细胞数量约为6.5×10⁵个细胞/毫升，而在内夫培养基中，细胞数量进一步增加（达到约2×10⁶个细胞/毫升）。5. 当细胞从限定培养基转移到内夫培养基时，未观察到胸苷激酶和核苷磷酸转移酶活性有显著差异，这与其他人报道的胸苷酸合成酶活性情况相反。
