THE DOMAIN OF APPLICABILITY OF CURRENTLY USED FORCE FIELDS FOR THE CALCULATION OF THE ACTIVITY OF ALKALI IONS AT PHYSIOLOGICAL IONIC STRENGTH

by Dr Chao Zhang

Tuesday 24 Nov 2009, 15:00 → 16:00 Europe/Rome

Aula 5 (Dipartimento di Fisica - Ed. E. Fermi)

Alkali ions are present in virtually all biological processes. Their energetic properties have been so far predicted mostly by MD or MC calculations based on effective potentials derived for infinite diluted conditions (i.e. a single ion surrounding solely by water molecules). However, the presence of a large ionic strength I near globular proteins or nucleic acids and in the active sites of of enzymes or channels is likely to limit the accuracy of the currently used potentials. Here we will discuss recent calculations of the activity coefficients for! K+,Na+ ions at increasing I.