Session J21 - General Biological Physics.
ORAL session, Tuesday morning, March 13
Room 604, Washington State Convention Center
The behavior of mobile linkers connecting two semi-flexible charged polymers, arising for example with DNA or F-actin in the presence of polyvalent counterions, is studied theoretically. The chain bending rigidity induces an effective repulsion between linkers at large distances while the inter-chain electrostatic repulsion leads to an effective short range inter-linker attraction. As a result, there is a rounded phase transition from a dilute one-dimensional linker gas where the chains form large loops between linkers to a dense disordered linker fluid connecting parallel chains (a ``railway track''). The rounded transition is characterized by large fluctuations in the inter-linker distance and occurs near the onset of bundling, where connected pairs become more favorable than isolated chains.