Реферат: The activity of oligomeric enzymes is sensitive to the formation of interprotein contact that make up the conformational lock. The mechanism for this is discussed in this article concerning the-galactosidase from Escherichia coli. The thermoinactivation curve, obtained at 40C, has induction period that may be ascribed to latent structural changes in conformational lock. The analysis of the kinetic curve has allowed us to calculate the minimum number of denaturation stages in the conformational lock (n = 3), i.e. tetramer becomes labile and capable of dissociation into two active dimers. These data support the kinetic scheme used to describe the dissociative inactivation of dimeric enzymes. The inactivation rate decreases in the presence of Mg2+. As metal binding sequences are placed in domains 1 and 3, therefore, tetramer interglobular contacts stabilize each subunit. Formation of tetramer inuences the activity of each subunit.

Библиографическая ссылка: Atyaksheva L.F. , Pilipenko O.S. , Poltorak O.M.
Mechanism of the Thermoinactivation of the β-Galactosidase from Escherichia Coli
Вестник Московского Университета. Серия 2: Химия. 2000. V.41. NS. P.95-97.

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