In order to investigate the significance of the fuzzy coat (disordered flanks) on the kinetic parameters of α-synuclein amyloid growth, we have performed bulk ThT aggregation experiments. We grew fibrils in quiescent conditions to maximize fibril length, and hence the ratio of surface area to the number of ends, prior to protease treatment. After "shaving" with proteinase K (pK) and subsequent inhibition of pK activity by PMSF we add fresh monomer to the samples that had ThT from the beginning, and ThT and fresh monomers were added to the samples that had been grown in the absence of ThT. Initial growth rates after the addition of fresh monomer are similar for all samples, however the increase in ThT fluorescence intensity of shaven fibrils ceases rather abruptly, and the ThT fluorescence decreases afterwards (Fig. ). In order to investigate whether the observed apparent cessation of fibril growth stems from a genuine decrease of the elongation rate constant, decreased ThT sensitivity or rather from increased higher order assembly of shaven fibrils, we compared the colloidal behavior of unmodified and shaven fibrils in a microscopic capillary assay. The fibrils were subjected to probe sonication right before the measurement, in order to start from a homogeneous fluorescence distribution, whereby no granularity was observed with our microscope.