Figure 6. Loss of tertiary interactions increases misfolding.

Native 8% polyacrylamide gel electrophoresis (PAGE) resolves native-like (I_C+N) and non-native conformers (lower mobility). WT and mutant ribozymes were refolded in 15 mM MgCl₂ before loading. Gels were run at 4 °C in 3 mM MgCl₂ to stabilize intermediates and prevent unfolding during electrophoresis (Rangan et al., 2003). Incubation at 37 °C or 50 °C before electrophoresis had no effect on the population of alternative structures, confirming they are equilibrium states.