Pontremoli S, Melloni E, Balestrero F, Franzi A T, De Flora A, Horecker B L
Proc Natl Acad Sci U S A. 1973 Feb;70(2):303-5. doi: 10.1073/pnas.70.2.303.
Seasonal variations in the properties of rabbit-liver fructose 1,6-bisphosphatase have now been linked to corresponding changes in the levels of proteolytic activity in the liver extracts. Incubation of native fructose 1,6-bisphosphatase with purified liver lysosomes causes a 3-fold increase in catalytic activity at pH 9.2, with a smaller, and variable, decrease in activity tested at pH 7.5. These changes in catalytic properties are accompanied by the appearance of a smaller subunit, as was previously reported for the enzyme treated with subtilisin. AMP, a negative modulator of fructose bisphosphatase activity, protects against this action of lysosomes. This proteolytic modification of fructose bisphosphatase by lysosomal enzymes may play a role in the modulation of gluconeogenesis.
现已发现，兔肝果糖1,6 - 二磷酸酶性质的季节性变化与肝脏提取物中蛋白水解活性水平的相应变化有关。天然果糖1,6 - 二磷酸酶与纯化的肝脏溶酶体一起孵育，在pH 9.2时催化活性增加3倍，而在pH 7.5测试时活性有较小且可变的降低。催化性质的这些变化伴随着一个较小亚基的出现，这与之前用枯草杆菌蛋白酶处理该酶的报道一致。AMP是果糖二磷酸酶活性的负调节剂，可防止溶酶体的这种作用。溶酶体酶对果糖二磷酸酶的这种蛋白水解修饰可能在糖异生的调节中起作用。
