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Determination of DNA cleavage specificity by esperamicins
M Lu1, Q Guo, B Krishnan
1Department of Chemistry, New York University, New York 10003.
Journal of Biomolecular Structure & Dynamics
|October 1, 1991
Summary
Esperamicins are antitumor antibiotics that cut DNA. Their core structure dictates DNA sequence preference, while sugar residues influence cleavage efficiency and DNA branching inhibits the process.
Area of Science:
- Medicinal Chemistry
- Molecular Biology
- Antibiotic Research
Background:
- Esperamicins are potent antitumor antibiotics.
- They possess unique diacetylenic ring systems.
- These systems generate DNA-cleaving diradicals upon thiol reaction.
Purpose of the Study:
- To investigate the sequence specificity of DNA scission by esperamicins.
- To determine the role of the diacetylenic ring core and sugar residues in DNA cleavage.
- To understand how DNA branching affects esperamicin activity.
Main Methods:
- Studied DNA scission by esperamicin A1 and its hydrolysis products (esperamicins C, D, E).
- Analyzed sequence preference for DNA cleavage.
- Investigated the influence of sugar residues and DNA branching on cleavage efficiency.
Main Results:
- The diacetylenic ring core determines the sequence specificity for DNA scission.
- Esperamicins C, D, and E retain a common sequence preference.
- Sugar residues influence cleavage efficiency, likely via non-specific DNA interactions.
- DNA branching locally inhibits esperamicin-mediated scission due to the core structure.
Conclusions:
- The core structure of esperamicins is the primary determinant of DNA sequence specificity.
- Sugar moieties modulate cleavage efficiency, and DNA branching presents a steric hindrance.
- Esperamicins represent a promising class of DNA-targeting antitumor agents.