Contributions to electrostatic interactions on protein transport in membrane systems

Several recent studies have demonstrated the importance of electrostatic in teractions on the transport of charged proteins through porous membranes. T he objective of this study is to compare predictions of available hydrodyna mic and partitioning models with experimental data for the sieving coeffici ent of ovotransferrin through both positively and negatively charged membra nes over a range of solution conditions. Model calculations were performed with all parameters evaluated from independent experimental measurements. T he membrane pore-size distribution was determined from dextran sieving data , and the membrane surface charge was evaluated from streaming potential me asurements. The model properly predicts the complex: effects of solution pH and ionic strength on protein transmission in the presence of both attract ive and repulsive electrical interactions. Model simulations were performed to highlight the key contributions to protein transport.