Magaña-Plaza I, Ruiz-Herrera J
J Bacteriol. 1967 Apr;93(4):1294-301. doi: 10.1128/jb.93.4.1294-1301.1967.
Urease of Proteus rettgeri is an inducible enzyme synthesized specifically in the presence of urea; urea analogues did not act as inducers. Once initiated, the biosynthesis of the enzyme proceeded as a constant fraction of the total protein formed. The rate of urease formation was affected by the carbon source used. In comparison with glycerol, glucose inhibited enzyme synthesis. The addition of ammonium ions to the inducing medium also decreased the rate of urease biosynthesis, and when ammonium ions were present urease activity and urea transport across the cell membrane were inhibited. A kinetic analysis of urease inhibition by ammonium ions, by use of a partially purified preparation of urease, showed that it was a competitive inhibition.
雷氏变形杆菌的脲酶是一种诱导酶，专门在有尿素存在的情况下合成；尿素类似物不能作为诱导剂。一旦开始，该酶的生物合成以形成的总蛋白的恒定比例进行。脲酶的形成速率受所用碳源的影响。与甘油相比，葡萄糖抑制酶的合成。向诱导培养基中添加铵离子也会降低脲酶生物合成的速率，并且当存在铵离子时，脲酶活性和尿素跨细胞膜的转运受到抑制。通过使用部分纯化的脲酶制剂对铵离子对脲酶的抑制作用进行动力学分析，结果表明这是一种竞争性抑制。
