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Dihydropteridine reductase from Escherichia coli
S G Vasudevan1, D C Shaw, W L Armarego
1Department of Biochemistry, John Curtin School of Medical Research, Australian National University, Canberra.
The Biochemical Journal
|October 15, 1988
Summary
Purified Escherichia coli dihydropteridine reductase is a dimeric enzyme containing FAD. It exhibits broad substrate specificity for pterins and cofactor versatility, utilizing both NADH and NADPH.
Area of Science:
- Biochemistry
- Enzymology
Background:
- Dihydropteridine reductase (DHPR) plays a crucial role in folate metabolism and neurotransmitter synthesis.
- Understanding the enzymatic properties of bacterial DHPR is essential for comparative biochemistry.
Purpose of the Study:
- To purify and characterize dihydropteridine reductase from Escherichia coli.
- To investigate its substrate specificity and cofactor utilization.
Main Methods:
- Purification of the enzyme to apparent homogeneity.
- Enzyme kinetics studies using various pterin substrates and cofactors (NADH, NADPH).
Main Results:
- The purified enzyme is a homodimer (Mr 27000 subunits) containing bound FAD.
- Demonstrated broad substrate specificity for pterin derivatives with both NADH and NADPH.
- Exhibited pterin-independent oxidoreductase activity with NADH and NADPH.
Conclusions:
- Escherichia coli DHPR is a versatile enzyme with significant cofactor flexibility.
- The enzyme's characteristics provide insights into bacterial pteridine metabolism and potential therapeutic targets.