Calculating Transition Energy Barriers and Characterizing Activation States for Steps of Fusion.

ABSTRACT: We use continuum mechanics to calculate an entire least energy pathway of membrane fusion, from stalk formation, to pore creation, and through fusion pore enlargement. The model assumes that each structure in the pathway is axially symmetric. The static continuum stalk structure agrees quantitatively with experimental stalk architecture. Calculations show that in a stalk, the distal monolayer is stretched and the stored stretching energy is significantly less than the tilt energy of an unstretched distal monolayer. The string method is used to determine the energy of the transition barriers that separate intermediate states and the dynamics of two bilayers as they pass through them. Hemifusion requires a small amount of energy independently of lipid composition, while direct transition fro

SUBMITTER: Ryham RJ 

PROVIDER: S-EPMC4788739 | biostudies-literature | 2016 Mar

REPOSITORIES: biostudies-literature