(b) The results in the table below were extracted from clinical reports of pediatric age infants (3 – 5 yr.) who had marked lactic acidosis, elevated blood ammonia, poor motor coordination, and showed mental retardation. From skin fibroblast cell cultures, enzyme assays were carried out, providing the results given below. PDH = pyruvate dehydrogenase; E1, E2, E3 signify the three enzyme activities of the PDH complex measured separately. It should be noted that measurement of the overall activity of the PDH complex employs a different assay system than those used for measurement of the activi- ties of the separate, individual component enzymes. PDH Complex activity Patient or Control E1 E2 E3 nmol/min/mg protein Native nmol/h/mg protein 3.69 ± 1.21 +dichloroacetate Patient 1 0.318 + 0.054 0.322 + 0.053 1.54 土0.29 15.1 + 3.0 Patient 2 0.050 ± 0,031 0.044 + 0.027 0.21 + 0.06 6.5 + 3.1 9.8 + 1.3 Patient 3 0.092 + 0.022 0.068 + 0.037 0.21 + 0.06 8.48 13.5 + 2.0 Control 1 0.932 ± 0.076 1.368 ± 0.085 1.33 ± 0.21 10.9 + 1.65 9.4 + 0.73 Control 2 1.07 + 0.067 1.360 + 0.065 11.73 + 2.1 13.1 + 2.2 (b1) ( strates ana cofactors added to measure enzyme activity have direct access to the PDH complex. In mammalian systems the PDH enzyme is regulated by reversible phosphorylation of three specific Ser residues. Dichloroacetate has been found to inhibit the PDH-kinase enzyme. Explain why addition of this reagent ensures measurement of the maximum activity of the PDH complex. Fibroblast cells are homogenized to disrupt cell and mitochondrial structure so that sub-
(b) The results in the table below were extracted from clinical reports of pediatric age infants (3 – 5 yr.) who had marked lactic acidosis, elevated blood ammonia, poor motor coordination, and showed mental retardation. From skin fibroblast cell cultures, enzyme assays were carried out, providing the results given below. PDH = pyruvate dehydrogenase; E1, E2, E3 signify the three enzyme activities of the PDH complex measured separately. It should be noted that measurement of the overall activity of the PDH complex employs a different assay system than those used for measurement of the activi- ties of the separate, individual component enzymes. PDH Complex activity Patient or Control E1 E2 E3 nmol/min/mg protein Native nmol/h/mg protein 3.69 ± 1.21 +dichloroacetate Patient 1 0.318 + 0.054 0.322 + 0.053 1.54 土0.29 15.1 + 3.0 Patient 2 0.050 ± 0,031 0.044 + 0.027 0.21 + 0.06 6.5 + 3.1 9.8 + 1.3 Patient 3 0.092 + 0.022 0.068 + 0.037 0.21 + 0.06 8.48 13.5 + 2.0 Control 1 0.932 ± 0.076 1.368 ± 0.085 1.33 ± 0.21 10.9 + 1.65 9.4 + 0.73 Control 2 1.07 + 0.067 1.360 + 0.065 11.73 + 2.1 13.1 + 2.2 (b1) ( strates ana cofactors added to measure enzyme activity have direct access to the PDH complex. In mammalian systems the PDH enzyme is regulated by reversible phosphorylation of three specific Ser residues. Dichloroacetate has been found to inhibit the PDH-kinase enzyme. Explain why addition of this reagent ensures measurement of the maximum activity of the PDH complex. Fibroblast cells are homogenized to disrupt cell and mitochondrial structure so that sub-
Biochemistry
9th Edition
ISBN:9781319114671
Author:Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.
Publisher:Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.
Chapter1: Biochemistry: An Evolving Science
Section: Chapter Questions
Problem 1P
Related questions
Question
Transcribed Image Text:(b) The results in the table below were extracted from clinical reports of pediatric age infants (3 – 5
yr.) who had marked lactic acidosis, elevated blood ammonia, poor motor coordination, and showed
mental retardation. From skin fibroblast cell cultures, enzyme assays were carried out, providing the
results given below. PDH = pyruvate dehydrogenase; E1, E2, E3 signify the three enzyme activities
of the PDH complex measured separately. It should be noted that measurement of the overall activity
of the PDH complex employs a different assay system than those used for measurement of the activi-
ties of the separate, individual component enzymes.
Patient or
PDH Complex activity
nmol/min/mg protein
Native
E1
E2
Ез
Control
+dichloroacetate
nmol/h/mg protein
Patient 1
0.318 + 0.054
0.322 + 0.053
1.54 0.29
3.69 + 1.21
15.1 + 3.0
Patient 2
0.050 ± 0,031
0.044 + 0.027
0.21 + 0.06
6.5 ± 3.1
9.8 ± 1.3
Patient 3
0.092 + 0.022
0.068 + 0.037
0.21 + 0.06
8.48
13.5 + 2.0
Control 1
0.932 + 0.076
1.368 + 0.085
1.33 + 0.21
10.9 + 1.65
9.4 + 0.73
Control 2
1.07 + 0.067
1.360 + 0.065
11.73 + 2.1
13.1 + 2.2
(b1) (
strates ana cofactors added to measure enzyme activity have direct access to the PDH complex. In
mammalian systems the PDH enzyme is regulated by reversible phosphorylation of three specific Ser
residues. Dichloroacetate has been found to inhibit the PDH-kinase enzyme. Explain why addition of
this reagent ensures measurement of the maximum activity of the PDH complex.
Fibroblast cells are homogenized to disrupt cell and mitochondrial structure so that sub-
Expert Solution
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
This is a popular solution!
Trending now
This is a popular solution!
Step by step
Solved in 2 steps
Recommended textbooks for you
Biochemistry
Biochemistry
ISBN:
9781319114671
Author:
Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.
Publisher:
W. H. Freeman
Lehninger Principles of Biochemistry
Biochemistry
ISBN:
9781464126116
Author:
David L. Nelson, Michael M. Cox
Publisher:
W. H. Freeman
Fundamentals of Biochemistry: Life at the Molecul…
Biochemistry
ISBN:
9781118918401
Author:
Donald Voet, Judith G. Voet, Charlotte W. Pratt
Publisher:
WILEY
Biochemistry
Biochemistry
ISBN:
9781319114671
Author:
Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.
Publisher:
W. H. Freeman
Lehninger Principles of Biochemistry
Biochemistry
ISBN:
9781464126116
Author:
David L. Nelson, Michael M. Cox
Publisher:
W. H. Freeman
Fundamentals of Biochemistry: Life at the Molecul…
Biochemistry
ISBN:
9781118918401
Author:
Donald Voet, Judith G. Voet, Charlotte W. Pratt
Publisher:
WILEY
Biochemistry
Biochemistry
ISBN:
9781305961135
Author:
Mary K. Campbell, Shawn O. Farrell, Owen M. McDougal
Publisher:
Cengage Learning
Biochemistry
Biochemistry
ISBN:
9781305577206
Author:
Reginald H. Garrett, Charles M. Grisham
Publisher:
Cengage Learning
Fundamentals of General, Organic, and Biological …
Biochemistry
ISBN:
9780134015187
Author:
John E. McMurry, David S. Ballantine, Carl A. Hoeger, Virginia E. Peterson
Publisher:
PEARSON