Reversible high hydrostatic pressure inactivation of phosphofructokinase from Escherichia coli

摘要: Tetrameric Escherichia coli phosphofructokinase dissociates reversibly on incubation under hydrostatic pressures of 80 MPa and above, yielding inactive dimers monomers. The transition is dependent upon enzyme concentration presence ligands. substrate, d-fructose 6-phosphate, which bridges the intersubunit interface at active site, produces a massive stabilization to pressure, whereas ATP, binds only one subunit, induces mild stabilization. Both positive allosteric regulator, GDP, negative phosphoenolpyruvate, whose binding sites lie other subunit interface, produce an intermediate effect. Of these ligands, ATP increases rate reactivation after depressurization.