caa a22 4500 445391723 CHVBK 20180317143048.0 cr unu---uuuuu 170323e20110401xx s 000 0 eng 10.1007/s10955-011-0172-4 doi (NATIONALLICENCE)springer-10.1007/s10955-011-0172-4 Marko John Department of Physics and Astronomy and Department of Molecular Biosciences, Northwestern University, 60208, Evanston, IL, USA aut Scaling of Linking and Writhing Numbers for Spherically Confined and Topologically Equilibrated Flexible Polymers [Elektronische Daten] [John Marko] Scaling laws for Gauss linking number Ca and writhing number Wr for spherically confined flexible polymers with thermally fluctuating topology are analyzed. For ideal (phantom) polymers each of N segments of length unity confined to a spherical pore of radius R there are two scaling regimes: for sufficiently weak confinement (R≫N 1/3) each chain has |Wr|≈N 1/2, and each pair of chains has average |Ca|≈N/R 3/2; alternately for sufficiently tight confinement (N 1/3≫R), |Wr|≈|Ca|≈N/R 3/2. Adding segment-segment avoidance modifies this result: for n chains with excluded volume interactions |Ca|≈(N/n)1/2 f(φ) where f is a scaling function that depends approximately linearly on the segment concentration φ=nN/R 3. Scaling results for writhe are used to estimate the maximum writhe of a polymer; this is demonstrated to be realizable through a writhing instability that occurs for a polymer which is able to change knotting topology and which is subject to an applied torque. Finally, scaling results for linking are used to estimate bounds on the entanglement complexity of long chromosomal DNA molecules inside cells, and to show how "lengthwise” chromosome condensation can suppress DNA entanglement. Springer Science+Business Media, LLC, 2011 Polymer topology nationallicence Confined polymers nationallicence Polymer statistics nationallicence Chromosome structure nationallicence Chromosome topology nationallicence Journal of Statistical Physics Springer US; http://www.springer-ny.com 142/6(2011-04-01), 1353-1370 0022-4715 142:6<1353 2011 142 10955 https://doi.org/10.1007/s10955-011-0172-4 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10955-011-0172-4 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Marko John Department of Physics and Astronomy and Department of Molecular Biosciences, Northwestern University, 60208, Evanston, IL, USA aut NATIONALLICENCE 773 0- Journal of Statistical Physics Springer US; http://www.springer-ny.com 142/6(2011-04-01), 1353-1370 0022-4715 142:6<1353 2011 142 10955 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer