Influence of DNA length on spermine-induced condensation. Importance of the bending and stiffening of DNA

• Published in: Biochimica et biophysica acta, Protein structure and molecular enzymology Vol. 909; no. 3; pp. 165 - 172
• Main Authors: Marquet, R, Wyart, A, Houssier, C
• Format: Journal Article
• Language: English
• Published: 01.01.1987
• ISSN: 0167-4838

Using DNA restriction fragments of 258 to 4362 base-pairs, the authors have investigated the influence of the DNA length on the condensation process induced by spermine, with the aid of electric dichroism measurements. The 258- and 436 bp fragments condensed into rod-like particles, while the fragments of 748 bp or more condensed into torus-shaped particles. The results suggest that a DNA molecule longer than the circumference of the toroids observed previously (680 bp) is required to serve as a nucleus for the growth of the condensed particles. The authors estimated that, in the case of DNA condensation by spermine, a decrease in the measured persistence length may occur, irrespective of the DNA flexibility, owing to the bending of the DNA molecule.