Continuum model predictions of the conformational equilibria of idealized p
olar and charged linear polymers in water are compared to complementary sim
ulations in explicit water. The continuum model of hydration predicts with
reasonable accuracy the conformational dependence of the hydration free ene
rgy of these solutes observed in the simulations. However, a prerequisite f
or accurate predictions is the optimization of the phenomenological paramet
ers inherent to the continuum model using the simulation results for a subs
et of the solutes, in this case the uncharged polymer and two amphiphilic p
olymer chains with a single positive or negative charge on one terminal gro
up. Our results demonstrate that the continuum model can be used to discrim
inate among the conformational preferences for different sequences of backb
one charges. Finally, an unexpected finding of this study is the stabilizat
ion in water of the more compact conformations of the polymer chains with a
fixed dipole moment. The driving force for this behavior is greater than t
he hydrophobic driving force and is electrostatic in nature. (C) 2001 Elsev
ier Science Ltd. All rights reserved.