E2 : Salts effect.

This experiment examined the effect of salts on the protein E2 assembly by measuring the hydrodynamic diameter through dynamic light scattering. Three salts NaCl, KCl and (NH4)2SO4 were used with increasing concentration suspended in two different buffers, Tris and sodium phosphate. The size of the E2 protein increases gradually with the increase in the concentration of both NaCl and (NH4)2SO4. This is consistent with Hofmeister effect which considers the interactions between the salts and the surrounding water. Electroselectivity effect which involves the specific anions binding to the amino acid can also be used to explain the phenomenon. KCl has stabilizing effect towards E2 assembly as no significant change in size is observed. We observed that the E2 protein retained its size when incubated in 50mM sodium phosphate, indicating that 50mM sodium phosphate buffer can better stabilize the E2 protein assembly than 20mM Tris buffer.Bachelor of Engineering (Chemical and Biomolecular Engineering