Sébastien Neukirch
Institut Jean le Rond d'Alembert
Centre National de la Recherche Scientifique
Université Pierre et Marie Curie
Paris, France

tel: +33 1 44 27 72 61
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e-mail: sebastien.neukirch (-atat-) upmc.fr

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Extracting DNA twist rigidity from experimental supercoiling data

Sébastien Neukirch

Physical Review Letters, 93 #19 (2004) 198107

Abstract : We use an elastic rod model with contact to study the extension versus rotation diagrams of single supercoiled DNA molecules. We reproduce quantitatively the supercoiling response of overtwisted DNA and, using experimental data, we get an estimation of the effective supercoiling radius and of the twist rigidity of B-DNA. We find that unlike the bending rigidity, the twist rigidity of DNA seems to vary widely with the nature and concentration of the salt buffer in which it is immerged.

PACS numbers : 36.20.-r, 62.20.Dc, 87.15.La, 05.45.-a

Key words : elastic twisted rods, contact, numerical path following, biomechanics.

download the-print version : PDF (150 ko) or PS (450 ko)

ArXiV : q-bio.BM/0402036
HAL (cnrs) : ccsd-00001150

download the journal version PDF ( 400 ko)