Inhibitory Effect on RT-PCR and Restriction Enzyme Activity by Ommochrome and Its Mechanism

Area of Science:

• Biochemistry
• Molecular Biology
• Pharmacology

Background:

• Ommochrome is a natural organic pigment found widely in Protostomia.
• Its physiological role and pharmacological effects are not well understood.

Purpose of the Study:

• To investigate the influence of ommochrome on RT-PCR and restriction enzyme activities.
• To elucidate the mechanism of ommochrome's inhibitory effects.

Main Methods:

• Purification of ommin from *Bombyx mori* diapause eggs.
• Biochemical assays to test inhibition of RT-PCR and restriction enzymes.
• Computational approaches including molecular docking, molecular dynamics simulation, and free energy calculation to study ommin/DNA interaction.

Main Results:

• Ommin inhibited both RT-PCR and restriction enzyme activities.
• The inhibitory mechanism is proposed to be direct binding to DNA, not enzyme inhibition.
• Computational analyses indicated ommin binds to DNA with strength comparable to actinomycin D, intercalating into the DNA structure.

Conclusions:

• Ommochrome exhibits pharmacological effects, specifically inhibiting DNA-related processes.
• The phenoxazine ring in ommochrome facilitates DNA intercalation, similar to actinomycin D.
• This study provides the first biochemical and computational evidence for ommochrome's pharmacological effects and DNA-binding mechanism.