Ionic associations/equilibria time scales

Starting from the pre-powerstroke state myosin complex with ADP and Pi tightly bound (summarized structure in Table I), the M.D.Pi is in rapid equilibrium with an actin-bound state on the microsecond-millisecond time scale. This is very dependent on ionic strength (Furch et al., 2000 White and Taylor, 1976) and is therefore probably a non-stereo-specific weak binding state and is controlled by the ionic interactions between loop 2 and the N-terminus of actin. Other ionic interactions may also be involved. This loose association between actin and myosin probably does not alter the overall conformation of myosin. 

Micelles are in dynamic equilibrium with their monomer surfactants. Two relaxation processes are related to this equilibrium, a fast one in the microsecond time domain associated with the exchange of individual monomers between the micelles and the bulk aqueous phase and a slower one on millisecond time-scale associated with the complete dissolution of the micelles into monomers [8], For example, the exit rate for the SDS anion from its micelle is about lO s, which is considered to be a diffusion-controlled process [8a]. Nonpolar molecules are usually attracted to the relatively hydrophobic inner core of micelles, whereas ionic reactants and products are either associated with the Stem and Gouy-Chapman layers or repelled from the micelles, depending on the sign of electrostatic interaction. For example, NMR studies show that nonpolar molecules such as benzene and naphthalene are... 

As electroneutrality is demanding, it is generally assumed that the field-assisted transport of charged species is more rapid than the transport of neutral species and, consequently, solvation equilibria can only be established slowly. Therefore, the equilibria associated with electronic, ionic and solvation processes may be established on quite different time scales, but at long enough time scales thermodynamics will prevail and processes will attain a state of global equilibrium. However, the relative rates of all the processes involved in the charge compensation are still an open question. 

---