caa a22 4500 467948186 CHVBK 20180405193739.0 cr unu---uuuuu 170328e20050101xx s 000 0 eng 10.1007/PL00021760 doi (NATIONALLICENCE)springer-10.1007/PL00021760 (NATIONALLICENCE)springer-10.1007/s10541-005-0053-z Metal-free PPi activates hydrolysis of MgPPi by an Escherichia coli inorganic pyrophosphatase [Elektronische Daten] [Ju. Vainonen, N. Vorobyeva, E. Rodina, T. Nazarova, S. Kurilova, Ju. Skoblov, S. Avaeva] Soluble inorganic pyrophosphatase from Escherichia coli (E-PPase) is a hexamer forming under acidic conditions the active trimers. We have earlier found that the hydrolysis of a substrate (MgPPi) by the trimers as well as a mutant E-PPase Asp26Ala did not obey the Michaelis-Menten equation. To explain this fact, a model has been proposed implying the existence of, aside from an active site, an effector site that can bind PPi and thus accelerate MgPPi hydrolysis. In this paper, we demonstrate that the noncompetitive activation of MgPPi hydrolysis by metal-free PPi can also explain kinetic features of hexameric forms of both the native enzyme and the specially obtained mutant E-PPase with a substituted residue Glu145 in a flexible loop 144-149. Aside from PPi, its non-hydrolyzable analog methylene diphosphonate can also occupy the effector site resulting in the acceleration of the substrate hydrolysis. Our finding that two moles of [32P]PPi can bind with each enzyme subunit is direct evidence for the existence of the effector site in the native E-PPase. MAIK "Nauka/Interperiodica”, 2005 inorganic pyrophosphatase nationallicence hexamer nationallicence trimer nationallicence effector site nationallicence substrate-induced activation nationallicence Glul45Gln substitution nationallicence Vainonen Ju Chemistry Faculty, Lomonosov Moscow State University, 119992, Moscow, Russia aut Vorobyeva N. Chemistry Faculty, Lomonosov Moscow State University, 119992, Moscow, Russia aut Rodina E. Chemistry Faculty, Lomonosov Moscow State University, 119992, Moscow, Russia aut Nazarova T. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119992, Moscow, Russia aut Kurilova S. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119992, Moscow, Russia aut Skoblov Ju Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, ul. Vavilova 32, 119991, Moscow, Russia aut Avaeva S. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119992, Moscow, Russia aut Biochemistry (Moscow) Nauka/Interperiodica 70/1(2005-01-01), 69-78 0006-2979 70:1<69 2005 70 10541 https://doi.org/10.1007/PL00021760 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/PL00021760 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Vainonen Ju Chemistry Faculty, Lomonosov Moscow State University, 119992, Moscow, Russia aut NATIONALLICENCE 700 1- Vorobyeva N. Chemistry Faculty, Lomonosov Moscow State University, 119992, Moscow, Russia aut NATIONALLICENCE 700 1- Rodina E. Chemistry Faculty, Lomonosov Moscow State University, 119992, Moscow, Russia aut NATIONALLICENCE 700 1- Nazarova T. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119992, Moscow, Russia aut NATIONALLICENCE 700 1- Kurilova S. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119992, Moscow, Russia aut NATIONALLICENCE 700 1- Skoblov Ju Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, ul. Vavilova 32, 119991, Moscow, Russia aut NATIONALLICENCE 700 1- Avaeva S. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119992, Moscow, Russia aut NATIONALLICENCE 773 0- Biochemistry (Moscow) Nauka/Interperiodica 70/1(2005-01-01), 69-78 0006-2979 70:1<69 2005 70 10541 NATIONALLICENCE 856 40 https://doi.org/10.1007/s10541-005-0053-z text/html Onlinezugriff via DOI Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE NATIONALLICENCE NL-springer