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Ginsenosides activate DNA polymerase delta from bovine placenta
1Department of Biochemistry, College of Medicine, University of Ulsan, Seoul, Korea.
Life Sciences
|January 1, 1995
Summary
Ginsenosides from Panax Ginseng activate DNA polymerase delta (pol delta) and its proofreading exonuclease activity. This activation, likely due to conformational changes, enhances DNA replication and repair mechanisms.
Area of Science:
- Biochemistry
- Molecular Biology
- Pharmacology
Background:
- DNA polymerase delta (pol delta) is crucial for DNA replication and repair.
- Ginsenosides are bioactive compounds derived from Panax Ginseng with various medicinal properties.
Purpose of the Study:
- To investigate the effect of ginsenosides on the activity of bovine placental DNA polymerase delta.
- To elucidate the mechanism by which ginsenosides modulate pol delta function.
Main Methods:
- Purification of DNA polymerase delta from bovine placenta.
- Enzyme kinetics assays to determine changes in Km and Vmax.
- Assays for 3'- to 5'-exonuclease activity.
- UV/Vis difference spectroscopy to study protein-ligand interactions.
Main Results:
- Ginsenosides significantly increased DNA polymerase delta activity (2.2-fold) in a dose-dependent manner.
- Activation involved a decrease in Km and a substantial increase in Vmax.
- Ginsenosides enhanced the 3'- to 5'-exonuclease (proofreading) activity of pol delta.
- Spectroscopic studies indicated that ginsenosides binding induced conformational changes in pol delta.
Conclusions:
- Ginsenosides activate both polymerase and exonuclease functions of DNA polymerase delta.
- The findings suggest that polymerase and exonuclease activities reside on the same protein molecule.
- Ginsenoside-induced conformational changes are likely responsible for the observed activation of pol delta.