A multi-enzyme complex Is made up of three polypeptide chains, A, B and C. A is associated with decarboxylase activity; B is a transacetylase, while C is a dehydrogenase. When the protein was placed in a nonpolar solvent, then run in PAGE, two protein bands were observed. Enzyme assays showed that one protein band exhibited decarboxylase activity while the other has both transacetylase and dehydrogenase activities. When the protein was also placed in an aqueous solvent at pH 5.0, then run in electrophoresis, two protein bands were also detected. Further enzyme assays also showed that one protein band exhibits transacetytase activity while the other has both decarboxylase and dehydrogenase activities. a. What types of non-covalent interactions are possible between A, B and C? b. Addition of urea, a reducing agent gave 4 bands in the PAGE profile with a subsequent loss of decarboxylase activity. What could be the reason for the observed result? Explain briefly in terms of the structure of the multi-enzyme complex.

A multi-enzyme complex Is made up of three polypeptide chains, A, B and C. A is associated with decarboxylase activity; B is a transacetylase, while C is a dehydrogenase. When the protein was placed in a nonpolar solvent, then run in PAGE, two protein bands were observed. Enzyme assays showed that one protein band exhibited decarboxylase activity while the other has both transacetylase and dehydrogenase activities. When the protein was also placed in an aqueous solvent at pH 5.0, then run in electrophoresis, two protein bands were also detected. Further enzyme assays also showed that one protein band exhibits transacetytase activity while the other has both decarboxylase and dehydrogenase activities. a. What types of non-covalent interactions are possible between A, B and C? b. Addition of urea, a reducing agent gave 4 bands in the PAGE profile with a subsequent loss of decarboxylase activity. What could be the reason for the observed result? Explain briefly in terms of the structure of the multi-enzyme complex.

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

Chapter4: Cells

Section: Chapter Questions

Problem 1ITD

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