[Energy of interaction in actinomycin-nucleotide complexes]

Area of Science:

• Biochemistry
• Molecular Biology
• Pharmacology

Context:

• Antibiotic delivery to tumor cells is crucial for cancer therapy.
• Actinomycin D (AMD) is a heterocyclic antibiotic with potential anticancer properties.
• Understanding drug-carrier interactions is key to optimizing drug delivery systems.

Purpose:

• To investigate the complexation of actinomycin D (AMD) with potential natural carriers.
• To quantify the interaction energy between AMD and various compounds using spectrophotometry.
• To evaluate the suitability of purine nucleotides, fragmented DNA, and liposomes as AMD carriers.

Summary:

• Spectrophotometry revealed that actinomycin D (AMD) interacts with caffeine, adenosine, guanosine, fragmented DNA, and phospholipid liposomes.
• AMD was found to adsorb onto and embed within purine clusters and fragmented DNA, particularly in unwound DNA regions.
• The interaction energy, calculated from spectral shifts, was higher for guanosine and fragmented DNA (3.3-3.7 kcal/mol) compared to caffeine and adenosine (2.4-2.7 kcal/mol).

Impact:

• This study identifies guanosine, adenosine, caffeine, and fragmented DNA as potential carriers for actinomycin D.
• The findings provide a basis for developing novel drug delivery strategies utilizing natural compounds for targeted cancer therapy.
• Quantifying interaction energies offers insights into the binding mechanisms and stability of drug-carrier complexes.