questions about ion residence times

          I am using MD to study the dynamics of a solvated Protein/DNA
 complex with explicit waters, Na+ and Cl-.
         We know of several studies on WATER residence times near both
 proteins and DNA (Wuttrich, Otting, Gueron, etc.)
         Is there any comparable research on ION experimental or
 theoretical residence times for Na+, Cl- or other monovalent ions which
 are coordinated with either proteins or DNA?
                                          Linjing Yang
                                          yanglj # - at - #