Research on Two-State Membranes.
Abstract
The basis for development of multiple resistance states in ultra-thin, lipid membranes (lipid bilayers) upon modification with various agents has been examined. The multistate behavior, with two regions of negative resistance, induced by a protein factor (EIM) from Enterobacter cloacae appears to be due to the formation of polar, cation-specific channels (pores), each having a discrete open and closed conductance state. The smooth negative resitsn The smooth negative resistance behavior in membranes containing large numbers of such channels is a statistical reflection of the potential-dependent switching of these channels between discrete open and closed states, rather than a graded response of each channel to potential. Other parameters, the closed state conductance and potentials required to induce switching, vary with membrane and medium composition. Other mechanisms for producing variable resistance in membranes were also studies. A two-state resistance produced by certain cationic dyes appears to be a space polarization effect. The transistor-like punchthrough produced by the antibiotic, alamethican is a high power function of alamethicin concentration, cation concentration and polarizing potential. These effects may be related to structuring of the lipid membrane by the cyclic peptide. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1971
- Accession Number
- AD0732226
Entities
People
- R. C. Bean