An Isaac Newton Institute Workshop

Protein-Protein Interactions in Vitro and in Vivo

Mesoscopic models for the effect of macromolecular crowding, macromolecular confinement, and surface adsorption upon protein associations

21st June 2004

Author: Allen P. Minton (NIH)

Abstract

A large fraction of the total volume of all biological fluid media is either occupied by soluble macromolecules, or lies within a distance of macromolecular dimension from the surface of an extended structural element such as a cytoskeletal fiber or a membrane. I will describe mesoscopic statistical-thermodynamic models for the excluded volume interaction of a globular protein with inert "background" macromolecules and model boundaries, and for nonspecific weakly attractive interaction between a globular protein and a planar surface. The results of calculations based upon these models will be presented, describing how nonspecific interactions of soluble proteins with features of the local environment are likely to affect specific associations between the soluble proteins. Model predictions will be compared with the result of experiment where relevant data are available.