Fig 3. Degree of clustering influences Syntaxin-1A mobility and cluster dynamics.

(A) Influence of clustering on Syntaxin-1A mobility. i) The diffusion constant of the cluster center is inversely proportional to the number of particles in the cluster. ii) The distribution of step lengths of single particles in a time period of 200 μs shows a wide variety of diffusive behaviors. Slow diffusion (small step length) is likely caused by particles in a clustered state, while faster diffusion (large step lengths) indicate to freely diffusing particles. (B) Cluster dynamics in relation to clustering degree. i) The rate of particles dissociating from a cluster as a function of the respective cluster size. ii) The distribution of residence times of particles in a cluster. (C) i) A sample trajectory of one Syntaxin-1A particle over the course of one simulation run. ii) Step length, number of neighbors and the size of the cluster in which the particle resides tracked for the sample trajectory.