Stabilization of the enzyme--substrate complex of the mutant Asp-67Asn inorganic pyrophosphatase from Escherichia coli by fluoride ions.
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.
Avaeva
S M
SM
Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119899, Russia. avaeva@libro.genebee.msu.su
Velichko
T I
TI
Vorobyeva
N N
NN
Kurilova
S A
SA
Nazarova
T I
TI
Sklyankina
V A
VA
D001224:Aspartic Acid / Q000235:genetics / Q000378:metabolism*; D004795:Enzyme Stability; D004926:Escherichia coli / Q000201:enzymology*; D043564:Inorganic Pyrophosphatase; D016297:Mutagenesis, Site-Directed; D011755:Pyrophosphatases / Q000235:genetics* / Q000378:metabolism; D012969:Sodium Fluoride / Q000494:pharmacology*
D001224:Aspartic Acid; D012969:Sodium Fluoride; D011755:Pyrophosphatases; D043564:Inorganic Pyrophosphatase