Effect of calcium, other ions, and pH on the reactions of barley peroxidase with hydrogen peroxide and fluoride. Control of activity through conformational change.

The Journal of Biological Chemistry
C B RasmussenK G Welinder

Abstract

Transient-state kinetic analysis of compound I formation for barley grain peroxidase (BP 1) has revealed properties that are highly unusual for a heme peroxidase but which may be relevant to its biological function. The enzyme shows very little reaction with H2O2 at pH > 5 and exhibited saturation kinetics at higher H2O2 concentrations (kcatapp increases from 1.1 s-1 at pH 4.5 to 4.5 s-1 at pH 3.1 with an enzyme-linked pKa < 3.7 (Rasmussen, C.B., Bakovic, M., Welinder, K. G., and Dunford, H. B. (1993) FEBS Lett. 321, 102-105)). In the present paper, it is shown that the presence of Ca2+ gives rise to biphasic kinetics for compound I formation, with a slow phase as described above and a fast phase that exhibits a second order rate constant more typical of a classical peroxidase (K1app = 1.5 x 10(7) M-1 S-1, which is pH-independent between 3.3 and 5.0). The amount of enzyme reacting in the fast phase increases with Ca2+ concentration (Kd = 4 +/- 1 mM at pH 4.0), although it is also moderately inhibited by Cl-. The absorption spectrum of BP 1, which appears to be a five-coordinate high spin ferric in the resting state changes insignificantly in the presence of Ca2+. In the presence of Cl-, it becomes six-coordinate high spin (Kd a...Continue Reading

References

Apr 1, 1992·Plant Molecular Biology·A JohanssonK G Welinder
Feb 1, 1991·Plant Molecular Biology·S K RasmussenJ Hejgaard
Apr 19, 1993·FEBS Letters·C B RasmussenH B Dunford
Feb 23, 1996·The Journal of Biological Chemistry·J N Rodriguez-LopezR N Thorneley
Mar 15, 1996·Structure·D J SchullerT L Poulos
Mar 25, 1997·Biochemistry·G R SutherlandS D Aust
Dec 24, 1997·Nature Structural Biology·M GajhedeT L Poulos

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Citations

Jul 17, 1998·Current Opinion in Chemical Biology·A T Smith, N C Veitch
Jun 27, 2002·European Journal of Biochemistry·Latesh LadEmma L Raven
Apr 7, 2011·Free Radical Biology & Medicine·Michal ShoreshNirit Bernstein
Dec 17, 2015·Journal of Biological Inorganic Chemistry : JBIC : a Publication of the Society of Biological Inorganic Chemistry·Chukwudi I NnamchiEmma L Raven
May 3, 2006·The FEBS Journal·Mamoudou H DickoWillem J H van Berkel
Sep 10, 2004·Biopolymers·Ana Sofia L CarvalhoEduardo Pinho e Melo
Feb 13, 2008·The FEBS Journal·Francesca PintusRosaria Medda
Jan 12, 2021·Journal of Biological Inorganic Chemistry : JBIC : a Publication of the Society of Biological Inorganic Chemistry·Prashant K SinghTej P Singh
Jul 10, 2002·Biochemistry·Alex LeeAlexander A Konstantinov
Jun 1, 2000·Journal of Inorganic Biochemistry·A M PrioriM Coletta

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