Correction - Reactions of Horseradish Peroxidase with Azide. Evidence for a Methionine Residue at the Active Site.

Biochemistry ◽  
1968 ◽  
Vol 7 (3) ◽  
pp. 1252-1252
Author(s):  
Arthur S. Brill ◽  
Ira. Weinryb
Keyword(s):  
Horseradish Peroxidase ◽  
Active Site ◽  
Methionine Residue

Kinetics of the oxidation of reduced nicotinamide adenine dinucleotide by horseradish peroxidase compounds I and II

1986 ◽  
Vol 64 (4) ◽  
pp. 323-327 ◽  
Author(s):  
Mohammed A. Kashem ◽  
H. Brian Dunford
Keyword(s):  
Horseradish Peroxidase ◽  
Active Site ◽  
Nicotinamide Adenine Dinucleotide ◽  
Ph Dependence ◽  
Transient State ◽  
Nicotinamide Adenine ◽  
Compound I ◽  
Single Ionization ◽  
Reduced Nicotinamide Adenine Dinucleotide ◽  
Kinetics Of

The transient state kinetics of the oxidation of reduced nicotinamide adenine dinucleotide (NADH) by horseradish peroxidase compound I and II (HRP-I and HRP-II) was investigated as a function of pH at 25.0 °C in aqueous solutions of ionic strength 0.11 using both a stopped-flow apparatus and a conventional spectrophotometer. In agreement with studies using many other substrates, the pH dependence of the HRP-I–NADH reaction can be explained in terms of a single ionization of pKa = 4.7 ± 0.5 at the active site of HRP-I. Contrary to studies with other substrates, the pH dependence of the HRP-H–NADH reaction can be interpreted in terms of a single ionization with pKa of 4.2 ± 1.4 at the active site of HRP-II. An apparent reversibility of the HRP-II–NADH reaction was observed. Over the pH range of 4–10 the rate constant for the reaction of HRP-I with NADH varied from 2.6 × 105 to5.6 × 102 M−1 s−1 and of HRP-II with NADH varied from 4.4 × 104 to 4.1 M−1 s−1. These rate constants must be taken into consideration to explain quantitatively the oxidase reaction of horseradish peroxidase with NADH.

Improvement of Peroxygenase Activity by Relocation of a Catalytic Histidine within the Active Site of Horseradish Peroxidase

Biochemistry ◽  
1998 ◽  
Vol 37 (30) ◽  
pp. 10828-10836 ◽  
Author(s):  
Marina I. Savenkova ◽  
Jane M. Kuo ◽  
Paul R. Ortiz de Montellano
Keyword(s):  
Horseradish Peroxidase ◽  
Active Site

Characterisation of a haem active-site mutant of horseradish peroxidase, Phe41 Val, with altered reactivity towards hydrogen peroxide and reducing substrates

1992 ◽  
Vol 207 (2) ◽  
pp. 507-519 ◽  
Author(s):  
Andrew T. SMITH ◽  
Stephen A. SANDERS ◽  
Roger N. F. THORNELEY ◽  
Julian F. BURKE ◽  
Robert R. C. BRAY
Keyword(s):  
Hydrogen Peroxide ◽  
Horseradish Peroxidase ◽  
Active Site

scholarly journals Affinity labelling with a deaminatively generated carbonium ion. Kinetics and stoicheiometry of the alkylation of methionine-500 of the lacZβ-galactosidase of Escherichia coli by β-d-galactopyranosylmethyl-p-nitrophenyltriazene

1978 ◽  
Vol 175 (2) ◽  
pp. 525-538 ◽  
Author(s):  
M L Sinnott ◽  
P J Smith
Keyword(s):  
Escherichia Coli ◽  
Active Site ◽  
Sequence Data ◽  
Free Enzyme ◽  
Irreversible Inhibitor ◽  
Methionine Residue ◽  
Complete Inactivation ◽  
Carbonium Ion ◽  
Affinity Labelling ◽  
Field Desorption Mass Spectrometry

1. beta-D-Galactopyranosylmethyl-p-nitrophenyltriazene is an active-site-directed irreversible inhibitor of Mg2+-bound and Mg2+-free lacZ beta-galactosidase from Escherichia coli. 2. The Mg2+-enzyme binds the inhibitor more tightly but the complex then decomposes less rapidly than is the case with Mg2+-free enzyme. 3. Loss of enzyme activity is a linear function of the fraction of enzyme protomers to which are attached beta-D-galactopranosyl[14C]methyl residues: complete inactivation of fully active enzyme results in incorporation of 0.91 equivalent of carbohydrate label per enzyme protomer. 4. When the beta-galactopyranosylmethyl cation is generated in the active site of Mg2+-enzyme, it is captured essentially completely by the protein, but in the active site of Mg2+-free enzyme it is only captured with an efficiency of 25%. 5. Labelled enzyme was carboxymethylated and digested with trypsin; acidic hydrolysis of the isolated tryptic peptide, and field-desorption mass spectrometry of the isolated radioactive derivative, showed it to be 2,5-dioxo-3[2-(beta-D-galactopyranosylmethylthio)ethyl]-1,6-trimethylenepiperazine. 6. This is considered to have arisen from labelling of the sulphur atom of a methionine residue adjacent to a proline residue. 7. The complete amino acid sequence of the molecule [Fowler & Zabin (1977) Proc. Natl. Acad. Sci. U.S.A. 74, 1507-1510] enables the labelled methionine residue to be identified as either Met-421 or Met-500. 8. Sequence data [Fowler, Zabin, Sinnott & Smith (1978) J. Biol. Chem. in the press] show the site of attack to be Met-500.

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