Smovzh S A, Zakharenko M O, Tupits'ka O M
National Agrarian University, Kyiv.
Ukr Biokhim Zh (1978). 1997 May-Jun;69(3):112-5.
It was shown that NAD(P)(+)-dependent glutamate dehydrogenase from bovine liver (EC 1.4.1.3) was activated under the action of ammonium chloride in concentration which corresponded to the level of ammonium in normal blood (2-10 mM). Ammonium chloride increases the activity of glutamate dehydrogenase 1.8 times. Having enhanced the level of ammonium chloride to the amount which corresponds to the level of ammonium ions in blood during the pathology (10-25 mM), this substance inhibited the enzyme activity of glutamate dehydrogenase. Influence of 20 mM ammonium chloride on IR-spectra of NAD(P)(+)-dependent glutamate dehydrogenase in the deuterium oxide solution leads to the widening of the absorption line at 3300 cm-1 toward the higher energy. It is supposed that inhibition action of ammonium ions on the activity of glutamate dehydrogenase is connected with partial destruction of stereoregular hydrogen bonds in the enzyme molecule.
结果表明，来自牛肝的NAD(P)(+)依赖性谷氨酸脱氢酶（EC 1.4.1.3）在氯化铵作用下被激活，其浓度与正常血液中的铵水平（2-10 mM）相当。氯化铵可使谷氨酸脱氢酶的活性提高1.8倍。当将氯化铵的水平提高到与病理状态下血液中铵离子水平相当的量（10-25 mM）时，该物质会抑制谷氨酸脱氢酶的酶活性。20 mM氯化铵对重水溶液中NAD(P)(+)依赖性谷氨酸脱氢酶的红外光谱的影响导致3300 cm-1处的吸收线向更高能量方向变宽。据推测，铵离子对谷氨酸脱氢酶活性的抑制作用与酶分子中立体规则氢键的部分破坏有关。
