Avaeva S M, Velichko T I, Vorobyeva N N, Kurilova S A, Nazarova T I, Sklyankina V A
Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119899, Russia.
Biochemistry (Mosc). 1999 Feb;64(2):169-74.
Magnesium-supported PPi hydrolysis by the mutant Asp-67Asn E. coli pyrophosphatase at saturating PPi and metal-activator concentrations in the presence of NaF is followed by a gradual decrease in the initial rate of PPi hydrolysis. The reaction occurs in two steps: first a complex containing enzyme, pyrophosphate, magnesium, and fluoride ions is immediately formed, then its conformation changes slowly. This enzyme--substrate complex stabilized by fluoride is partially active and can be isolated by the removal of excess fluoride by gel-filtration.
在存在氟化钠的情况下，当焦磷酸（PPi）和金属激活剂浓度达到饱和时，突变型天冬氨酸-67-天冬酰胺大肠杆菌焦磷酸酶催化的镁依赖的PPi水解反应中，PPi水解的初始速率会逐渐降低。该反应分两步进行：首先，立即形成一种包含酶、焦磷酸、镁离子和氟离子的复合物，然后其构象缓慢变化。这种由氟离子稳定的酶-底物复合物具有部分活性，可通过凝胶过滤去除过量氟离子来分离。
