Simulation of two-dimensional streptavidin crystallization

We present lattice Monte Carlo simulations of the growth of streptavidin is lands at a biotinylated lipid layer. The model employed takes into account attractive anisotropic lateral interactions between streptavidin tetramers. With a minimal set of interactions, we reproduce the formation of rectangu lar islands experimentally observed at pH greater than or equal to 9.0. Spe cifically, we analyze two scenarios of the island growth. First, if strepta vidin is rapidly adsorbed at t = 0 (stepwise coverage change without ongoin g adsorption), the average linear island size is found to grow according to the Lifshitz-Slyozov law, R proportional to t(1/3). Second, if the island growth occurs in parallel with streptavidin adsorption limited by diffusion in the solution, the Lifshitz-Slyozov law is also applicable, but only at the late stage, when the streptavidin coverage is appreciable. Proteins 200 1; 43:489-498. (C) 2001 Wiley-Liss, Inc.