sentences:  The NH2-terminal extension decreases the folding rate of the precursor form of MBP relative to its mature form by at least 5 fold, but it has no effect on the unfolding rate.The equilibrium unfolding of MBP can be modelled by a two-state mechanism with a stability ∆G(H2O) equal to 9.45 kcal mol−1 at 25 °C, pH 7.6.MBP is exported into the periplasmic space of "E. coli".