Statistical thermodynamic theory for helix-coil transitions involving poly- and oligonucleotides. II. The case of partial binding.

Abstract

Statistical thermodynamic properties of order—disorder transitions in one-dimensional lattices can be derived from partition functions formulated by means of the matrix method. Direct application is made here to systems comprised of doubly stranded molecular complexes analogous to that proposed for deoxyribonucleic acid (DNA). In the present treatment one strand (the lattice) is taken to be a polynucleotide to which oligonucleotides are attached through complementary hydrogen bonding. The oligonucleotides may be partially bound. Both the case that the species are homopolymeric and the case that they are copolymeric are investigated. Exact numerical and asymptotic results are presented which display the functional dependence of the transition temperature upon the degree of polymerization (D. P.) of the various species.