“Self-assembly of biological photonic devices: Insights into reflectin protein function”
Cephalopods are rich with evolved optical devices with sub-wavelength structure that self-assemble into bioluminescent light guides that provide camouflage; focusing mirrors that attract mates; and isotropic diffusers for luring prey. These optical devices are all made from a structural protein called “reflectin” that, in a living squid skin cell self-assembles into a wide range of dielectrically layered, hierarchically ordered structures. It is the variable geometry of these structures resulting from different reflectin protein complements that allows them to interact usefully. The two different dielectric materials in the devices are formed from condensed reflectin protein within the cell, making a dense layer, and the intercalating extracellular space, forming a sparse layer. We have been investigating the structure-function properties of these proteins by considering them to be amphiphilic polymers with interesting interfacial properties. This talk will discuss the proteins' evolution, results of molecular dynamics simulations, and initial SAXS and SANS results that form an initial hypothesis about reflectins-bearing cells' biophysical functions and mechanisms of assembly.
