Department of Physics2024-11-0920100378-437110.1016/j.physa.2009.12.0632-s2.0-81555216065http://dx.doi.org/10.1016/j.physa.2009.12.063https://hdl.handle.net/20.500.14288/8860We investigate the impact of supercoil period and nonzero supercoil formation energy on the thermal denaturation of a circular DNA. Our analysis is based on a recently proposed generalization of the Poland–Scheraga model that allows the DNA melting to be studied for plasmids with circular topology, where denaturation is accompanied by formation of supercoils. We find that the previously obtained first-order melting transition persists under the generalization discussed. The dependence of the size of the order-parameter jump at the transition point and the associated melting temperature are obtained analytically.PhysicsJournal Article1873-2119279491200025Q23848