HIERARCHICAL ORGANIZATION IN AGGREGATES OF PROTEIN MOLECULES

The aggregation of proteins into small clusters is studied by atomic f orce and electron microscopy. Scaling laws and fractal behaviour in th e growth of the aggregates and in the correlation between aggregates i s seen. A phase diagram of the aggregation process where the protonic concentration of the solution and the density of protein are varied sh ows the existence of specific growth processes resulting in different branch-like structures. The resulting structures are strongly influenc ed by the shape of each protein molecule. Lysozyme and ribonuclease ar e found to form spherical structures with a narrow size distribution.