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Published on: December 9, 2017
Human NAD(+)-dependent mitochondrial malic enzyme. cDNA cloning, primary structure, and expression in Escherichia
G Loeber1, A A Infante, I Maurer-Fogy
1Ernst Boehringer Institut, Vienna, Austria.
The Journal of Biological Chemistry
|February 15, 1991
Summary
Researchers cloned and expressed human mitochondrial NAD(+)-dependent malic enzyme. This enzyme is crucial for converting amino acid carbon to pyruvate in rapidly proliferating and tumor cells.
Area of Science:
- Biochemistry
- Molecular Biology
- Enzymology
Background:
- Mitochondrial NAD(+)-dependent malic enzyme (EC 1.1.1.40) is implicated in amino acid metabolism in proliferating and tumor cells.
- Understanding its properties is key to metabolic research.
Purpose of the Study:
- To clone and characterize the human NAD(+)-dependent mitochondrial malic enzyme.
- To express a functional enzyme in Escherichia coli for further study.
Main Methods:
- cDNA cloning of the human enzyme.
- Amino acid sequencing.
- Heterologous expression in E. coli.
Main Results:
- A 1,923 bp cDNA encoding a 584-amino acid protein (65.4 kDa precursor) was identified.
- Sequence comparison revealed conserved regions with other malic enzymes, but also significant unique stretches.
- Recombinant enzyme expressed in E. coli exhibited identical kinetic and allosteric properties to the native human enzyme.
Conclusions:
- The study successfully cloned, sequenced, and expressed functional human mitochondrial NAD(+)-dependent malic enzyme.
- The recombinant enzyme serves as a reliable model for studying enzyme mechanisms and allosteric regulation.
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