The purification and properties of sucrose-phosphate synthetase from spinach leaves: the involvement of this enzyme and fructose bisphosphatase in the regulation of sucrose biosynthesis.
The purification and properties of sucrose-phosphate synthetase from spinach leaves: the involvement of this enzyme and fructose bisphosphatase in the regulation of sucrose biosynthesis.
复制标题
菠菜叶蔗糖磷酸合成酶的纯化和性质：该酶和果糖双磷酸酶参与蔗糖生物合成的调节。
DOI：
10.1016/0003-9861(81)90363-5
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发表时间：
1981
影响因子：
3.9
通讯作者：
D. Walker
中科院分区：
文献类型：
--
作者：
S. Harbron;C. Foyer;D. Walker
研究了菠菜叶片蔗糖-磷酸合成酶（EC 2.4.1.14）和胞质果糖-1,6-二磷酸酶（EC 3.1.3.11）的性质。这两种酶被认为在控制蔗糖合成中起重要作用。从叶片组织中提取蔗糖-磷酸合成酶的研究尚未得到详细的研究，我们报道了一种用AH-Sepharose 4B层析50倍纯化该酶的技术。这种方法将酶从干扰分析程序的污染物中解放出来，活性很少或没有损失。部分纯化的酶对0.8 mm的果糖6-磷酸的akm为7.1 mm的udp -葡萄糖。果糖1,6-二磷酸，无机磷酸盐和UDP是强抑制剂。这些抑制模式表明酶的作用是有序的bi-bi或Theorell-Chance机制。部分纯化的胞质果糖-1,6-双磷酸酶不仅受到先前报道的AMP的抑制，而且还受到果糖6-磷酸和UDP的抑制。根据我们的观察，我们得出结论，蔗糖的生物合成确实是由这两种酶控制的，似乎蔗糖的合成速度在很大程度上取决于叶绿体中磷酸三糖和ATP的供应。
The properties of spinach leaf sucrose-phosphate synthetase (EC 2.4.1.14) and cytosolic fructose-1,6-bisphosphatase (EC 3.1.3.11) have been studied. These two enzymes have been considered to be important in the control of sucrose synthesis. Sucrose-phosphate synthetase from leaf tissue has not been studied in detail previously and we report a technique for purifying this enzyme 50-fold by chromatography on AH-Sepharose 4B. This method frees the enzyme from contaminants which interfere with assay procedures with little or no loss of activity. The partially purified enzyme has aKmfor UDP-glucose of 7.1 mmand for fructose 6-phosphate of 0.8 mm. Fructose 1,6-bisphosphate, inorganic phosphate and UDP are strong inhibitors. The inhibition patterns of these suggest that the enzyme operates either by an ordered bi-bi or a Theorell-Chance mechanism. Partially purified cytosolic fructose-1,6-bisphosphatase is not only inhibited by AMP as previously reported, but is also inhibited by fructose 6-phosphate and UDP. From our observations, we conclude that sucrose biosynthesis is indeed controlled through these two enzymes and it appears that the rate of sucrose synthesis is largely dependent upon the supply of triose phosphate and ATP from the chloroplast.