Amplitude, wave form, and temperature dependence of bilayer ripples in thePβ′phase

Scanning tunneling microscopy—freeze-fracture replication has provided a quantitative, high resolution description of the wave form and amplitude of rippled bilayers in the $P_{{\beta }^{\prime }}$ phase of dimyristoylphosphatidylcholine. The ripples are uniaxial and asymmetric, with a temperature dependent amplitude of 2.4 nm near the chain melting temperature decreasing to zero at the chain crystallization temperature. The wavelength of 11 nm does not change with temperature. The observed ripple shape and the temperature induced structural changes are not predicted by any current theory.