| Bio | 
| Paper |
Benjamin L. Yoder
Goshen College
Subject Listing - Biology
Advisor: Dr. Carl Helrich
Friday, Poster Session 5, Presentation Kiosk 11 B, Health & Fitness Center
DECAY DYNAMICS OF NYSTATIN CHANNELS IN THE PRESENCE OF STEROL MICROSTRUCTURES ON MEMBRANES
Nystatin (nys) is an antifungal agent that preferentially forms ion channels in membranes containing the sterol ergosterol (erg). The structure of the nystatin channel is not clear, although it is clear that multiple nystatin monomers require a sterol-rich membrane for aggregation. When nys/erg containing vesicles are fused to a sterol-free membrane, characteristic spike changes in membrane conductance are observed. The decay of a conductance spike is generally step-wise linear and the time of decay is a strong function of [erg]. These data indicate interdependence among the nys/erg channels. A model has been developed in which nys channels form at the boundary of a lipid/erg superlattice rafts (SLR) and channel decay is determined by erg diffusion from the SLR. This model was tested using Monte Carlo (MC) simulations for the diffusion current from the SLR. The MC simulations predict a constant diffusion current from the SLR which results in a rate of loss of channels which is linear in time. The steps in the decay are understood in terms of multiple SLRs and SLRs with fissions. The model then provides a complete understanding of the decay scheme observed experimentally. This interpretation also predicts previously confusing data relating conductance spike height to vesicle diameter.
Advisor: Dr. Carl Helrich, Professor, Physics, Goshen College, Goshen, IN