Topological defects and the optimum size of DNA condensates.
Under a wide variety of conditions, the addition of condensing agents to dilute solutions of random-coil DNA gives rise to highly compact particles that are toroidal in shape. The size of these condensates is remarkably constant and is largely independent of DNA molecular weight and basepair sequence, and of the nature of condensing agent (e.g., multivalent cation, polymers, or added cosolvent). We show how this optimum size is determined by the interactions between topological defects, which unavoidably strain the circumferentially wound DNA strands in the torus.
Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569 USA. parks@chem.ucla.edu
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Gelbart
D001482:Base Composition; D001483:Base Sequence; D004247:DNA / Q000737:chemistry* / Q000302:isolation & purification; D004548:Elasticity; D008956:Models, Chemical; D008958:Models, Molecular; D008970:Molecular Weight; D009690:Nucleic Acid Conformation; D012996:Solutions; D012997:Solvents; D013329:Structure-Activity Relationship; D013816:Thermodynamics
D012996:Solutions; D012997:Solvents; D004247:DNA