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Caffeine inhibits DNA polymerase I from Escherichia coli: studies in vitro

R Balachandran, A Srinivasan

    Carcinogenesis
    |January 1, 1982
    PubMed

    Insights

    Caffeine inhibits DNA replication by targeting DNA polymerase enzymes from E. coli and Micrococcus luteus. This competitive inhibition is most effective with complex DNA templates and reaches maximum effect within 30 minutes.

    Area of Science:

    • Molecular Biology
    • Biochemistry
    • Enzymology

    Background:

    • DNA polymerase is crucial for DNA replication and repair.
    • Caffeine is a widely consumed psychoactive compound with known biological effects.

    Purpose of the Study:

    • To investigate the effect of caffeine on DNA polymerase activity.
    • To determine the mechanism of caffeine's inhibition on DNA replication.

    Main Methods:

    • In vitro DNA replication assays using purified DNA polymerases.
    • Enzyme kinetics and time-course studies were performed.
    • Various DNA templates including activated adenovirus, T4, calf thymus DNA, and synthetic templates were used.

    Main Results:

    • Caffeine significantly inhibited DNA polymerase I (E. coli) and its large fragment.
    • DNA polymerase from Micrococcus luteus was also inhibited by caffeine.
    • Inhibition was more pronounced with complex DNA templates compared to synthetic ones.
    • Caffeine's inhibitory effect reached maximum by 30 minutes of incubation.
    • Enzyme kinetic studies revealed competitive inhibition with respect to the DNA template.

    Conclusions:

    • Caffeine acts as an inhibitor of bacterial and archaeal DNA polymerases.
    • The mechanism of inhibition is competitive with the DNA template.
    • These findings suggest potential roles for caffeine in modulating DNA replication processes.

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