What does peroxidase do to guaiacol?
Peroxidase is easily extracted from turnips by homogenization in buffer. The broken cells release peroxidase (as well as other enzymes) into the buffer. If the enzyme is present, the peroxide is quickly converted to water and oxygen, and the oxygen reacts with the Guaiacol to produce a brown product, oxidized Guaiacol.
How does peroxidase react with hydrogen peroxide?
Peroxidases, also known as catalases, are also an oxidoreductase class of enzymes, which catalyze oxidoreduction reactions. The peroxidase enzyme catalyzes the decomposition of hydrogen peroxide into water and molecular oxygen (see illustration). Catalase is a haem-containing enzyme.
Is guaiacol a substrate for peroxidase?
With guaiacol as substrate, acidic pH optima have often been reported for the apoplastic peroxidases of several plant species (Hendriks et al., 1991; Melo et al., 1996; Nair and Showalter, 1996).
Does guaiacol oxidize?
The presence of guaiacol stimulates the oxidation of NADPH by the MPO/H2O2 system in a concentration-dependent manner. Concomitantly, the accumulation of biphenoquinone (BQ), the final steady-state product of guaiacol oxidation, is lowered, and even inhibited completely, at high concentrations of NADPH.
What is the role of guaiacol reaction?
1 Guaiacol. Reaction of guaiacol in high-temperature and supercritical water leads to products like catechol, phenol, and o-cresol through primary hydrolysis and to high-molecular weight compounds as the major products of pyrolysis [74].
Is hydrogen peroxide the same as peroxidase?
Both enzymes use one molecule of hydrogen peroxide to form a high valent iron intermediate named Compound I (Cpd I). However, whereas catalase Cpd I oxidizes a second H(2)O(2) molecule to oxygen, peroxidases use this intermediate to oxidize other substrates rather than H(2)O(2).
How is peroxidase activity determined?
Peroxidase activity was measured by determining the absorbance of yellow product at 450 nm. Increase in absorbance was directly proportional to the peroxidase activity.
What is a guaiacol used for?
Guaiacol is used in traditional dental pulp sedation, and has the property of inducing cell proliferation; guaiacol is a potent scavenger of reactive oxygen radicals and its radical scavenging activity may be associated with its effect on cell proliferation.
What does guaiacol do in this lab?
In this experiment, an indicator for oxygen will be used. The compound guaiacol has a high affinity for oxygen, and in solution, it binds instantly with oxygen to form tetraguaiacol, which is brownish in color. The greater the amount of oxygen gas produced, the darker brown the solution will become.
Is guaiacol a substrate?
Guaiacol was used as the target phenolic compound because it is a widely known substrate used for assaying peroxidase activity in the extract from different sources.
What is guaiacol solution?
Guaiacol is an agent thought to have disinfectant properties and used as an expectorant. Guaiacol is a phenolic natural product first isolated from Guaiac resin and the oxidation of lignin. Guaiacol is also present in wood smoke, as a product of pyrolysis of lignin.
How do you make hydrogen peroxide solution from guaiacol?
Dissolve 240mg guaiacol in water and make up to 100mL. It can be stored frozen for many months. » Hydrogen peroxide solution (0.042% = 12.3mM). Dilute 0.14mL of 30% H 2 O 2 to 100 mL with water. The extinction of this solution should be 0.485 at 240nm. Prepare freshly.
Is guaiacol a good substrate for lignin peroxidase?
Pre-steady-state kinetic analyses demonstrated that guaiacol is a good substrate for both compounds I and II, the two- and one-electron oxidized enzyme intermediates, respectively, of lignin peroxidase. The rate constant for the reaction with compound I is 1.2 x 10(6) M-1s-1.
What is the role of guaiacol in peroxidase assay?
Guaiacol is used as substrate for the assay of peroxidase. The resulting oxidized (dehydrogenated) guaiacol is probably more than one compound and depends on the reaction conditions.
Is guaiacol-dependent peroxidase activity in the absence or the presence of typical peroxidase effectors?
Guaiacol-dependent activity in the absence or presence of typical peroxidase effectors Peroxidase activity was measured with the partially purified enzymes after cation exchange chromatography in the presence of 8.26 mmguaiacol and 8.8 mmH2O2at pH 7.0 as described in “Materials and Methods.” Data are given as mean ± sd(n).