Overcharging of a macroion by an oppositely charged polyelectrolyte

Complexation of a polyelectrolyte with an oppositely charged spherical macr oion is studied for both salt-free and salty solutions. When a polyelectrol yte winds around the macroion, its turns repel each other and form an almos t equidistant solenoid. It is shown that this repulsive correlations of tur ns lead to the charge inversion: more polyelectrolyte winds around the macr oion than it is necessary to neutralize it. The charge inversion becomes st ronger with increasing concentration of salt and can exceed 100%. Monte-Car lo simulation results agree with our analytical theory. (C) 2001 Elsevier S cience B.V. All rights reserved.