水稻根谷氨酰胺合成酶同工酶某些性质研究

水稻根谷氨酰胺合成酶同工酶某些性质研究 SOME PROPERTIES OF GLUTAMINE SYNTHETASE ISOZYMES IN RICE ROOTS 刘翠兰 Liu Cuilan 1 first-author 张楚富 Zhang Chufu 1 林清华 Lin Qinghua 1 李常健 Li Changjian 1 李泽松 Li Zesong 1 王许莲 Wang Xulian 1 武汉大学生命科学学院 武汉大学生命科学学院 College of Life Sciences, Wuhan University, Wuhan 430072, China) Shaobing Peng, John Bennett College of Life Sciences, Wuhan University, Wuhan 430072, China) Shaobing Peng, John Bennett 对水稻根两种不同形式的谷氨酰胺合成酶（ＧＳｒａ和ＧＳｒｂ）进行了动力学性质研究．ＧＳｒａ对热比较稳定，而ＧＳｒｂ比较敏感；ＧＳｒａ的最适温度为５５℃，ＧＳｒｂ为４３℃．ＧＳｒａ和ＧＳｒｂ的最适ｐＨ都为７．５．ＧＳｒａ对Ｌ－谷氨酸、羟胺和ＡＴＰ的表观Ｋｍ分别为４．１６、０．６０和０．３４，而ＧＳｒｂ分别为１５．７３、０．６０和０．５８．ＭＳＯ对两者均表现为竞争性抑制作用 The kinetic propeties on glutamine synthetase isozymes in rice roots were studied after separation by ion exchange chromatography and native PAGE. GSra was more heat stable than GSra. GSra exhibited maximum activity at 55℃, the optimum temperature of GSrb was 43℃. The synthetase assay pH optima were 7.5 for both GSra and GSrb. The Km values of GSra for L glutamate, NH 2OH, and ATP were 4.16, 0.6 and 0.34 mmol/L, respectively, whereas that of GSrb were 15.23, 0.6, and 0.58 mM, respectively. MSO exhibited a competitive inhibition for both GSra and GSrb. 水稻根 谷氨酰胺合成酶 同工酶 动力学 rice root glutamine synthetase isozyme kinetics S511.101 国家自然科学基金,湖北省自然科学基金,国际水稻研究所基金 1998-06-01 2021-04-01 6