Gerard Jannink

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2014 Solutions of polyelectrolyte are studied by small angle neutron scattering for c > 0.5 x 10-2 g. cm -3. The function S(q) is characterized by a small value of S’(q ~ 0) and one broad maximum for higher q’s (10-2 q 2 x 10-1 Å-1) . The effect of polyion concentration and addition of salt are studied : the position of the maximum varies with polyion(More)
We discuss the requirement of type II DNA topoisomerase in the process of mitotic chromosome condensation. Using a known model describing the collapse of homopolymers, we propose that the compaction process necessitates a change in the topological state (i.e., a self-knotting) of the chromosomal chain. We argue that the enzymes are necessary to reach the(More)
In the course of anaphase, the chromosomal DNA is submitted to the traction of the spindle. Several physical problems are associated with this action. In particular, the sister chromatids are generally topologically intertwined at the onset of anaphase, and the removal of the intertwinings results from a coupling between the enzymatic action of type II DNA(More)
2014 We report results of quasi-elastic neutron scattering experiments on concentrated polyelectrolyte solutions in water without added salt. The polyion is sulphonated polystyrene, associated successively with sodium and tetramethylammonium counterions. In this second case, all possible configurations of deuterated and non deuterated charged components are(More)
Several experimental data support the notion that the recognition of DNA crossovers play an important role in the multiple functions of topoisomerase II. Here, a theoretical analysis of the possible modes of assembly of yeast topoisomerase II with right and left-handed tight DNA crossovers is performed, using the crystal coordinates of the docking partners.(More)