THE MELTING TRANSITION IN SINGLE AND MULTIBILAYER PHOSPHOLIPID TUBULES

The melting transition of phospholipid-based microcylindrical tubules, has been investigated for single and multibilayer tubules, using high -field, high-resolution magnetic birefringence and precision microcalo rimetry techniques. Measurements of the magnetically induced optical p alarizability anisotropy and the heat capacity, reveal that the transi tion of multibilayer tubules is discontinuous, consistent with the mel ting behavior of crystalline lipid phases. Single bilayer tubules exhi bit a melting transition that conforms with hexatic-smectic phase tran sitions.