7. Chalcone isomerase catalyzes the reaction illustrated below. A series of modification experiments were performed on this enzyme to identify which amino acid residues might be in the active site and which might promnote the cyclization reaction. HO. OH HO Но. Explain the following results: A) Acetic anhydride treatment inhibited enzyme activity. B) Pyrocarbonate inhibited activity and was found to modify 7 residues. However, this enzyme only contains 6 His and modification of these did not affect activity. C) lodoacetate inhibited activity but this effect couly be decreased in the presence of substrate or product. D) Methane methanethiol sulfonate modified the enzyme but did not inhibit catalytic turnover. In addition, this modification was reversed in the presence of B-mercaptocthanol. (keNYons Rengent

7. Chalcone isomerase catalyzes the reaction illustrated below. A series of modification experiments were performed on this enzyme to identify which amino acid residues might be in the active site and which might promnote the cyclization reaction. HO. OH HO Но. Explain the following results: A) Acetic anhydride treatment inhibited enzyme activity. B) Pyrocarbonate inhibited activity and was found to modify 7 residues. However, this enzyme only contains 6 His and modification of these did not affect activity. C) lodoacetate inhibited activity but this effect couly be decreased in the presence of substrate or product. D) Methane methanethiol sulfonate modified the enzyme but did not inhibit catalytic turnover. In addition, this modification was reversed in the presence of B-mercaptocthanol. (keNYons Rengent

Biology: The Dynamic Science (MindTap Course List)

4th Edition

ISBN:9781305389892

Author:Peter J. Russell, Paul E. Hertz, Beverly McMillan

Publisher:Peter J. Russell, Paul E. Hertz, Beverly McMillan

Chapter6: Energy, Enzymes, And Biological Reactions

Section: Chapter Questions

Problem 8TYK: Which of the following statements about the allosteric site is true? a. The allosteric site is a...

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