The bulge loop nearest neighbor parameters for free energy change were reported in:
Mathews, D.H., Sabina, J., Zuker, M. and Turner, D.H. (1999) Expanded sequence dependence of thermodynamic parameters provides improved prediction of RNA secondary structure. J. Mol. Biol., 288, 911-940.
The experimental data for the fit of the parameters were taken from:
1. Fink,
T.R. and Crothers, D.M. (1972) Free energy of imperfect nucleic acid helices, I. The bulge defect. J. Mol. Biol., 66, 1-12.
2. Groebe, D.R.
and Uhlenbeck, O.C. (1989) Thermal stability of RNA
hairpins containing a four-membered loop and a bulge nucleotide. Biochemistry, 28, 742-747.
3. Longfellow, C.E., Kierzek,
R. and Turner, D.H. (1990) Thermodynamic and spectroscopic study of bulge loops
in oligoribonucleotides. Biochemistry, 29,
278-285.