Phosphofructokinase from Fasciola hepatica: activation by phosphorylation and other regulatory properties distinct from the mammalian enzyme.
Phosphofructokinase from Fasciola hepatica: activation by phosphorylation and other regulatory properties distinct from the mammalian enzyme.
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来自肝片形吸虫的磷酸果糖激酶：通过磷酸化和与哺乳动物酶不同的其他调节特性来激活。
DOI：
10.1016/0003-9861(87)90327-4
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发表时间：
1987
影响因子：
3.9
通讯作者：
Mansour,TE
中科院分区：
文献类型：
--
作者：
Kamemoto,ES;Iltzsch,MH;Lan,L;Mansour,TE
肝片吸虫的磷酸果糖激酶被从该生物体中分离的环AMP依赖性蛋白激酶的催化亚基磷酸化。与天然磷酸果糖激酶相比，磷酸化的吸虫磷酸果糖激酶对其底物Fru-6-P的表观Km值低7倍，对ATP（酶的主要抑制剂）的表观Km值高8倍（0.5V）。先前报道了在哺乳动物蛋白激酶催化亚基磷酸化后吸虫磷酸果糖激酶的活化（E. S. Kamemoto和T. E. Mansour（1986）J. Biol Chem.261，4346-4351）。从肝吸虫分离的蛋白激酶的催化亚基，其磷酸果糖激酶的磷酸化位点与哺乳动物酶的磷酸化位点相似。最大磷酸盐掺入量为0.3 molP/mol原聚体。发现天然酶含有1.3molP/mol的原聚体。与吸虫磷酸果糖激酶相反，哺乳动物心脏酶的活性在磷酸化后略有下降。在哺乳动物磷酸果糖激酶中观察到的变构相互作用对酸性pH的依赖性在吸虫酶中没有观察到。不同于哺乳动物磷酸果糖激酶，在碱性pH（8.0）下观察到吸虫酶的变构动力学。发现Fluke磷酸果糖激酶对柠檬酸盐的抑制相对不敏感，柠檬酸盐是已知的哺乳动物酶的有效抑制剂。Fru-2，6-P2是一种来自多种来源的磷酸果糖激酶的有效修饰剂，被发现可以激活天然的和磷酸化的吸虫磷酸果糖激酶。发现最有效的吸虫磷酸果糖激酶激活剂是Fru-2，6-P2、AMP和磷酸化。结果表明，该虫体内Fru-2，6-P_2的含量为29 ± 1.3 nmol/g湿重，该含量可调节酶活性，即Fru-2，6-P_2合成酶。我们的研究结果表明磷酸化和Fru-2，6-P2在调节吸虫磷酸果糖激酶中的生理作用。
Phosphofructokinase from the liver fluke,Fasciola hepatica, was phosphorylated by the catalytic subunit of cyclic AMP-dependent protein kinase isolated from this organism. Phosphorylated fluke phosphofructokinase had a sevenfold lower apparentKmfor its substrate, Fru-6-P, and an eightfold higher 0.5Voptfor ATP, the enzyme's primary inhibitor, than native phosphofructokinase. Activation of fluke phosphofructokinase following phorphorylation by a mammalian protein kinase catalytic subunit was previously reported (E. S. Kamemoto and T. E. Mansour (1986)J. Biol Chem.261, 4346–4351). The catalytic subunit of protein kinase isolated from the liver fluke phosphorylated sites on fluke phosphofructokinase similar to those phosphorylated by the mammalian enzyme. Maximal phosphate incorporation was 0.3 molP/mol of protomer. The native enzyme was found to contain 1.3 molP/mol of protomer. In contrast to fluke phosphofructokinase, activity of the mammalian heart enzyme was slightly decreased following phosphorylation. The dependence of allosteric interaction on an acidic pH observed with the mammalian phosphofructokinase was not observed with the fluke enzyme. Unlike mammalian phosphofructokinase, allosteric kinetics of the fluke enzyme was observed at alkaline pH (8.0). Fluke phosphofructokinase was found to be relatively insensitive to inhibition by citrate, a known potent inhibitor of the mammalian enzyme. Fru-2,6-P2, a potent modifier of phosphofructokinase from a variety of sources, was found to activate both native and phosphorylated fluke phosphofructokinase. The most potent activators of fluke phosphofructokinase were found to be Fru-2,6-P2, AMP, and phosphorylation. The endogenous level of Fru-2,6-P2in the flukes was determined to be 29 ± 1.3 nmol/g wet wt, a level that may well modulate enzyme activity, Fru-6-P,2-kinase, the enzyme responsible for synthesis of Fru-2,6-P2, was found to be present in the flukes. Our results suggest physiological roles for phosphorylation and Fru-2,6-P2in regulation of fluke phosphofructokinase.
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DOI：
10.1016/0006-3002(59)90298-7
发表时间：
1959
期刊：
Biochimica et biophysica acta
影响因子：
--
作者：
Tag E. Mansour
通讯作者：
Tag E. Mansour
肌肉磷酸果糖激酶的磷酸和去磷酸形式的特性。
DOI：
--
发表时间：
1982
期刊：
The Journal of biological chemistry
影响因子：
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作者：
Foe,LG;Kemp,RG
通讯作者：
Kemp,RG
脑磷酸果糖激酶的同工酶组成和磷酸化。
影响因子：
3.9
作者：
Foe,LG;Kemp,RG
通讯作者：
Kemp,RG
DOI：
10.1016/s0021-9258(18)34722-7
发表时间：
1982-04
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
L. Hue;P. Blackmore;H. Shikama;A. Robinson-Steiner;J. Exton
通讯作者：
L. Hue;P. Blackmore;H. Shikama;A. Robinson-Steiner;J. Exton
灌注大鼠心脏中磷酸果糖激酶的调节。
DOI：
--
发表时间：
1985
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Narabayashi,H;Lawson,JW;Uyeda,K
通讯作者：
Uyeda,K