title: Tightly bound pyrophosphate in Escherichia coli inorganic pyrophosphatase.
abstract: Hexameric inorganic pyrophosphatase of Escherichia coli contains about 1 mol/mol of 'structural' pyrophosphate, which survives gel filtration and prolonged incubation with Mg2+, does not exchange with medium phosphate and pyrophosphate but is removed with 0.8 M perchloric acid. The site of pyrophosphate binding seems to be another than the active site. An additional 0.9 mol of enzyme-bound pyrophosphate is formed in the presence of phosphate and Mg2+ but this pyrophosphate is in fast equilibrium with medium phosphate and appears to be bound to the active site.
authors.affiliation: A.N.Belozersky Laboratory of Molecular Biology and Bioorganic Chemistry, Moscow, USSR.
authors.forename: A A
authors.initials: AA
authors.lastname: Shestakov
authors.forename: A A
authors.initials: AA
authors.lastname: Baykov
authors.forename: S M
authors.initials: SM
authors.lastname: Avaeva
mesh_terms: D000818:Animals; D001665:Binding Sites; D011756:Diphosphates / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology*; D008099:Liver / Q000201:enzymology; D011755:Pyrophosphatases / Q000378:metabolism*; D051381:Rats; D015003:Yeasts / Q000201:enzymology
chemical_list: D011756:Diphosphates; D011755:Pyrophosphatases