Monte Carlo simulations of protein micropatterning in biomembranes: effects of immobile nanofeatures with reduced diffusivity

Nanoscopic features of reduced diffusivity have long been suggested to contribute to plasma membrane heterogeneity. Two prominent examples of this are highly dynamic lipid-mediated assemblies ('membrane rafts') and shells of annular lipids surrounding transmembrane proteins. Here, we simulated a micropatterning experiment, where such nanoscopic features are immobilized in specific areas within the live cell plasma membrane. We evaluated the effect of patterned nanofeatures of different sizes and diffusivities on the spatial distribution and two-dimensional mobility of tracer molecules. From this, we derive empirical models that describe the long-range tracer mobility as a function of the nanofeature density. In turn, our results facilitate the determination of nanofeature dimensions from micropatterning experiments.