A BIFUNCTIONAL THYMIDYLATE SYNTHETASE-DIHYDROFOLATE REDUCTASE IN PROTOZOA
A BIFUNCTIONAL THYMIDYLATE SYNTHETASE-DIHYDROFOLATE REDUCTASE IN PROTOZOA
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DOI：
10.1016/0166-6851(84)90070-7
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发表时间：
1984-01-01
影响因子：
1.5
通讯作者：
SANTI, DV
中科院分区：
文献类型：
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作者：
GARRETT, CE;CODERRE, JA;SANTI, DV
胸苷酸合成酶和二氢叶酸还原酶作为双功能蛋白存在于原生动物的许多物种中，这些物种跨越亚界的不同群体。酶在凝胶过滤和对二氢叶酸还原酶特异的亲和层析柱上共纯化。该双功能蛋白存在于革螨属、利什曼原虫属、锥虫属、疟原虫属、艾美耳球虫属、四膜虫属和裸藻属中。由于未知的原因，在溶组织内阿米巴和E.入侵。由于这两种酶在原生动物中都没有单独的蛋白质存在，因此这种双功能蛋白质很可能广泛存在于这些原始的真核生物中。在大多数情况下，天然蛋白质的表观大小大约是具有胸苷酸合成酶的亚基的两倍。除了一个例外，亚基大小接近于在其他来源中发现的单独酶的亚基大小的总和。
Thymidylate synthetase and dihydrofolate reductase exist as a bifunctional protein in a number of species of protozoa which span diverse groups of the subkingdom. The enzymes copurify upon gel filtration and on affinity chromatography columns specific for dihydrofolate reductase. The bifunctional protein was found in species of Crithidia, Leishmania, Trypanosoma, Plasmodium, Eimeria, Tetrahymena and Euglena. For reasons unknown, neither enzyme could be detected in Entamoeba histolytica or E. invadens. Since neither enzyme has yet been found as a separate protein in protozoa, it is likely that the bifunctional protein is widespread among these primitive eukaryotes. In most cases, the apparent size of the native protein is approximately twice that of the subunit possessing thymidylate synthetase. With 1 exception, the subunit sizes are close to the sum of the subunit sizes of the separate enzymes found in other sources.