OVALBUMIN DIFFUSION AT LOW IONIC-STRENGTH

Ovalbumin mutual diffusivities and intradiffusivities have been determined by the synthetic boundary and pulsed field gradient NMR techniques as a function of protein concentration at pH 5.5 and 4 mM sodium acetate. The pulsed field gradient technique provides efficient and reliable estimates of the ovalbumin intradiffusion coefficient and, in conjunction with the macroscopic boundary-relaxation technique and independent measures of the protein activity coefficient, offers a means of comparing the magnitudes of the frictional coefficients for mutual diffusion and intradiffusion. Ovalbumin diffusivities determined by quasi-elastic light scattering are intermediate in value between those experimentally determined by the NMR and boundary-relaxation techniques.