RESTRUCTURING OF SPATIAL-ORGANIZATION OF CIRCULAR DNA IN LIQUID-CRYSTALLINE DISPERSIONS

Restructuring of spatial organization of supercoiled and nicked DNA mo lecules in liquid-crystalline (LC) dispersions under micrococcal nucle ase treatment was studied. Exposure to micrococcal nuclease was shown to result in the transformation of ''nonspecific'' into cholesteric pa cking of circular DNA in dispersion particles. This transformation was described in the framework of the Kolmogorov-Avramy equation; the par ameters of this equation differed significantly for various topologica l forms of DNA. The liquid-crystalline state of DNA expands the range of ionic conditions which support efficient micrococcal nuclease actio n.