Comparison of ion solvation and partitioning free energies with membrane translocation free energies

Range Table - link kcal/mol
Organism Generic
Reference Vorobyov I. et al., Ion-induced defect permeation of lipid membranes. Biophys J. 2014 Feb 4 106(3):586-97. doi: 10.1016/j.bpj.2013.12.027. Supporting material p.10 table S2PubMed ID24507599
Method Abstract: "[Investigators] have explored the mechanisms of uncatalyzed membrane ion permeation using atomistic simulations and electrophysiological recordings." P.586 left column top paragraph: "Here [investigators] have used molecular dynamics (MD) simulations and electrophysiological measurements to better understand and quantify charge-membrane transport processes."
Comments Main text p.590 left column 2nd paragraph: "The PMFs [potentials of mean force] for ion permeation across DPPC [1,2-dipalmitoyl-sn-glycero-3-phosphocholine] bilayers are compared in Fig. 4. All ions experience a triangular- or Λ-shaped free-energy profile, where the barriers are similar, varying between 24.1 (for Cl−) and ∼25.8 kcal/mol (for K+). This similarity of barriers despite the different chemistries, sizes, hydration free energies (varying by >30 kcal/molTable S2), and charges of the ions, is astonishing. Using the experimental model bilayer, DPhPC [1,2-diphytanoyl-sn-glycero-3-phosphocholine], for comparison, the barrier for GuanH+ is found to be only 0.6 kcal/mol less than that for DPPC." See notes beneath table. GuanH+=[arginine side chain analog guanidinium]
Entered by Uri M
ID 112548