Heller J S, Rostomily R, Kyriakidis D A, Canellakis E S
Proc Natl Acad Sci U S A. 1983 Sep;80(17):5181-4. doi: 10.1073/pnas.80.17.5181.
In Escherichia coli, the biosynthetic ornithine and arginine decarboxylases (EC 4.1.1.17 and 4.1.1.19, respectively) are responsible for the biosynthesis of polyamines from ornithine and arginine, respectively. When E. coli cells are grown in the presence of increasing amounts of polyamines, a progressive increase in the amount of antizyme 1 and antizyme 2 occurs. The amino acid compositions of antizymes 1 and 2 show them to be basic proteins; antizyme 1 has an amino acid composition similar to that of the E. coli histone-like protein HU and of the eukaryotic histone H2B; antizyme 2 is characterized by an unusually high arginine content. We find these proteins to be specific inhibitors of both the biosynthetic ornithine decarboxylase and the biosynthetic arginine decarboxylase. They do not inhibit the corresponding biodegradative ornithine and arginine decarboxylases, nor do they inhibit lysine decarboxylase or S-adenosylmethionine decarboxylase. These properties of the antizymes favor their function in the regulation of polyamine biosynthesis in E. coli. The ability of the purified antizymes to inhibit the ornithine and arginine decarboxylases is stabilized in acidic buffers and is lost upon prolonged exposure to solutions at neutral or basic pH.
在大肠杆菌中，生物合成型鸟氨酸脱羧酶和精氨酸脱羧酶（分别为EC 4.1.1.17和4.1.1.19）分别负责从鸟氨酸和精氨酸生物合成多胺。当大肠杆菌细胞在多胺含量不断增加的环境中生长时，抗酶1和抗酶2的量会逐渐增加。抗酶1和抗酶2的氨基酸组成表明它们是碱性蛋白质；抗酶1的氨基酸组成与大肠杆菌类组蛋白HU和真核组蛋白H2B相似；抗酶2的特点是精氨酸含量异常高。我们发现这些蛋白质是生物合成型鸟氨酸脱羧酶和生物合成型精氨酸脱羧酶的特异性抑制剂。它们不抑制相应的生物降解型鸟氨酸和精氨酸脱羧酶，也不抑制赖氨酸脱羧酶或S-腺苷甲硫氨酸脱羧酶。抗酶的这些特性有利于它们在大肠杆菌多胺生物合成调控中的作用。纯化的抗酶抑制鸟氨酸和精氨酸脱羧酶的能力在酸性缓冲液中稳定，而在中性或碱性pH溶液中长时间暴露后会丧失。
