Biolayer interferometry provides a robust method for detecting DNA binding small molecules in microbial extracts.

Area of Science:

• Biochemistry
• Natural Product Chemistry
• Drug Discovery

Background:

• DNA replication is a key target for cancer therapeutics, with many drugs derived from natural products.
• Isolating DNA-binding small molecules from natural sources is traditionally challenging and time-consuming.
• Current screening methods often rely on laborious bioactivity-guided fractionation.

Purpose of the Study:

• To evaluate biolayer interferometry (BLI) as a rapid screening tool for identifying DNA-targeting small molecules from natural product sources.
• To demonstrate the utility of BLI in detecting various DNA binding interactions.
• To screen a microbial library for novel DNA-binding compounds.

Main Methods:

• Verified BLI's DNA-binding detection using designed oligonucleotides and known DNA-binding agents (e.g., actinomycin D, doxorubicin).
• Screened over 100 bacterial extracts using BLI for DNA-binding activity.
• Employed binding-guided isolation to identify active compounds from positive extracts.

Main Results:

• BLI accurately detected DNA binding affinities comparable to literature values for known agents.
• Identified three highly active bacterial extracts with significant DNA-binding potential.
• Isolated and identified echinomycin, actinomycin V, and chartreusin as the active principles.

Conclusions:

• BLI provides a novel, sensitive, and cost-effective biosensor approach for medium-throughput screening of complex chemical libraries.
• This method accelerates the discovery of natural product-based DNA-targeting anticancer agents.
• The study validates BLI as a powerful tool for natural product drug discovery.