Sandbox Reserved 1477: Difference between revisions

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[[Media:Movie compressed compressed.mp4]]

The super compressed version of my movie. Sorry I have to compress it a lot in order to fit the size of the file allowed to upload.

== Function ==

GOX in fungus functioned as an anti-bacterial and anti-fungal reagent by producing the hydrogen peroxide. It could also assist in plant infection, lignin degradation and lowering pH of the environment. The hydrogen peroxide produced allows the fungus competing with other types of bacteria or fungi, especially those which could not produce hydrogen peroxide. The fungus with GOX will be protected by the '''catalase''' in its cell, which could break down hydrogen peroxide into water and oxygen “peacefully” without hurting the cell. The existence of hydrogen peroxide in the concentration of '''micromolar''' level with the presence of GOX could inhibit the growth of cells <ref>PMID: 18330562</ref>.

Another product, δ-gluconolactone, could be hydrolyzed either enzymatically or non-enzymatically to gluconic acid <ref>PMID: 19374943</ref>. This reaction is going to decrease the pH value of the environment of the fungus, which, according to Dr. Wong, makes GOX able to function as a preservative.

The enzyme is very selective. Specific constant, which has a lot of different names in different essays, is used to describe the rate of the reaction. It is defined as k_cat/K_m , which is a much fairer and more representative way comparing to mention k_cat or K_m only because the reaction rate is expressed as v=(k_cat 〖[E]〗_t S)/(K_m+[S]). Comparing to the specific constant of the enzyme binding to the β-D-glucose, When binding to the 2-deoxyglucose, which has a similar structure as the original reactant β-D-glucose, the enzyme shows a 10-fold lower specific constant; when binding to the D-mannose, which also has a great structural similarity comparing with β-D-glucose, the enzyme shows a 400-fold lower specific constant; when binding to D-Galactose, the enzyme shows a 1000-fold lower specific constant; when binding to D-Xylose, the enzyme shows a 3000-fold lower specific constant <ref>PMID:10216293</ref>.

== Energetic ==

FAD acts as an electron carrier during the reaction. The '''GOX-FAD''' form of the enzyme is reduced to the '''GOX-FADH2''' form during the reaction. The FAD oxidizes the β-D-glucose to δ-gluconolactone and being reduced to FADH2; the oxygen molecule is reduced to the hydrogen peroxide with the electrons transferred. This process is supported by a protonated '''His''' residue, which thus functions best at lower pH. Although the mechanism of the reaction had been clearly studied, the actual roles of the residues of the active sites are still unclear <ref>PMID: 10749686</ref>.

Sandbox Reserved 1477: Difference between revisions

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@@ Line 30: / Line 30: @@
 [[Media:Movie compressed compressed.mp4]]
 The super compressed version of my movie. Sorry I have to compress it a lot in order to fit the size of the file allowed to upload.
 == Function ==
 GOX in fungus functioned as an anti-bacterial and anti-fungal reagent by producing the hydrogen peroxide. It could also assist in plant infection, lignin degradation and lowering pH of the environment. The hydrogen peroxide produced allows the fungus competing with other types of bacteria or fungi, especially those which could not produce hydrogen peroxide. The fungus with GOX will be protected by the '''catalase''' in its cell, which could break down hydrogen peroxide into water and oxygen “peacefully” without hurting the cell. The existence of hydrogen peroxide in the concentration of '''micromolar''' level with the presence of GOX could inhibit the growth of cells <ref>PMID: 18330562</ref>.
+Another product, δ-gluconolactone, could be hydrolyzed either enzymatically or non-enzymatically to gluconic acid <ref>PMID: 19374943</ref>. This reaction is going to decrease the pH value of the environment of the fungus, which, according to Dr. Wong, makes GOX able to function as a preservative.
+The enzyme is very selective. Specific constant, which has a lot of different names in different essays, is used to describe the rate of the reaction. It is defined as k_cat/K_m , which is a much fairer and more representative way comparing to mention k_cat or  K_m only because the reaction rate is expressed as v=(k_cat 〖[E]〗_t S)/(K_m+[S]). Comparing to the specific constant of the enzyme binding to the β-D-glucose, When binding to the 2-deoxyglucose, which has a similar structure as the original reactant β-D-glucose, the enzyme shows a 10-fold lower specific constant; when binding to the D-mannose, which also has a great structural similarity comparing with β-D-glucose, the enzyme shows a 400-fold lower specific constant; when binding to D-Galactose, the enzyme shows a 1000-fold lower specific constant; when binding to D-Xylose, the enzyme shows a 3000-fold lower specific constant <ref>PMID:10216293</ref>.
 == Energetic ==
 FAD acts as an electron carrier during the reaction. The '''GOX-FAD''' form of the enzyme is reduced to the '''GOX-FADH2''' form during the reaction. The FAD oxidizes the β-D-glucose to δ-gluconolactone and being reduced to FADH2; the oxygen molecule is reduced to the hydrogen peroxide with the electrons transferred. This process is supported by a protonated '''His''' residue, which thus functions best at lower pH. Although the mechanism of the reaction had been clearly studied, the actual roles of the residues of the active sites are still unclear <ref>PMID: 10749686</ref>.