Figure 4. Effect of aggregation inhibitors on thermal association of lysozyme in solution.

(a) Relative decrement in the diffusion coefficient of lysozyme without any arginine (-●-) and with: 100 mM (-○-), 200 mM (-△-), 300 mM (-◊-), 400 mM (-∇-) and 500 mM (-◻-) of arginine is plotted as a function of temperature. (Lines are spline curves plotted to guide the eye on the trend). (b) Temperature induced changes in the diffusion coefficient of lysozyme without benzyl alcohol (-●-), and with 1%(-◻-), 2% (-∆-) and 3% (-◊-) of benzyl alcohol is presented. (Lines are spline curves plotted to guide the eye on the trend). (c) Images of orthorhombic and tetragonal crystals of lysozyme formed in the presence of arginine and (d) benzyl alcohol at 45 °C. Importantly, spherulites were observed neither with arginine nor with benzyl alcohol crystal set-ups. (e) Structure of lysozyme with bound arginine and (F) benzyl alcohol superimposed with the heat induced dimeric and trimeric association of lysozyme. (Insets) Ligands are shown in stick representations.