2015/12/08 by Tirthankar Banerjee, Banerjee, Tirthankar, Abhik Basu +1
Biochemistry, Genetics and Molecular Biology · Chemistry · Engineering · #Electrostatics and Colloid Interactions #FOS: Physical sciences #Lipid Membrane Structure and Behavior #Nanopore and Nanochannel Transport Studies #Soft Condensed Matter (cond-mat.soft) #Statistical Mechanics (cond-mat.stat-mech)
paper · pdf · doi:10.48550/arxiv.1512.03418
openalex publication_date 2015/12/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Whether live cell membranes show miscibility phase transitions (MPTs), and if so, how they fluctuate near the transitions remain outstanding unresolved issues in physics and biology alike. Motivated by these questions we construct a generic hydrodynamic theory for lipid membranes that are active, due for instance, to the molecular motors in the surrounding cytoskeleton, or active protein components in the membrane itself. We use this to uncover a direct correspondence between membrane fluctuations and MPTs. Several testable predictions are made: (i) generic \em active stiffening with orientational long range order (flat membrane) or \em softening with crumpling of the membrane, controlled by the \em active tension and (ii) for mixed lipid membranes, capturing the nature of putative MPTs by measuring the membrane conformation fluctuations. Possibilities of both first and second order MPTs in mixed active membranes are argued for. Near second order MPTs, active stiffening (softening) manifests as a \em super-stiff (super-soft) membrane. Our predictions are testable in a variety of \em in-vitro systems, e.g., live cytoskeletal extracts deposited on liposomes and lipid membranes containing active proteins embedded in a passive fluid.