Effects of Excluded Surface Area and Adsorbate Clustering on Surface Adsorption of Proteins. II. Kinetic Models

摘要: Models for equilibrium surface adsorption of proteins have been recently proposed (Minton, A. P., 2000. Biophys. Chem. 86:239 -247) in which negative cooperativity due to area exclusion by adsorbate molecules is compensated a variable extent the formation heterogeneous population monolayer clusters adsorbed protein molecules. In present work this concept extended treat kinetics adsorption. It postulated that may grow via two distinct kinetic pathways. The first pathway diffusion monomer edge preexisting cluster and subsequent accretion. second consists direct deposition solution onto upper (solution-facing) ("piggyback" deposition) incorporation into cluster. Results calculations time course adsorption, carried out different limiting models structure energetics, show absence piggyback deposition, enhancement tendency can reduce, but not eliminate, adsorbate. Apparently noncooperative (Langmuir-like) positively cooperative progress curves, qualitatively similar those reported several published experimental studies, require significant fraction total flux through pathway. According model developed here above-mentioned reference, should be common concomitant non-site-specific proteins, provide an important mechanism assembly organized "protein machines" vivo.