Probability of Alamethicin Conductance States Varies with Nonlamellar Tendency of Bilayer Phospholipids
Abstract
With few exceptions (1-3), membrane lipids are usually regarded as a kind of filler or passive solvent for membrane proteins. Yet, cells exquisitely control membrane composition. Many phospholipids found in plasma membrane bilayers favor packing into inverted hexagonal bulk phases (4-6). It was suggested that the strain of forcing such lipids into a bilayer may affect membrane protein function, such as the operation of trans-membrane channels (7- 10, 6). To investigate this, we have inserted the peptide alamethicin into bilayer membranes composed of lipids of empirically determined inverted hexagonal phase 'spontaneous radii' Ro, which will have expectably different degrees of strain when forced into bilayer form. We observe a correlation between measured Ro and the relative probabilities of different conductance states. States of higher conductance are more probable in Dioleoyl Phosphatidyl Ethanolamine (DOPE), the lipid of highest curvature, 1/Ro, than in Dioleoyl Phosphatidyl Choline (DOPC), the lipid of lowest curvature.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1993
- Accession Number
- ADA264957
Entities
People
- A. M. Bezrukov
- I. Vodyanoy
- M. W. Tate
- S. L. Keller
- S. M. Gruner
Organizations
- Princeton University