EXPERIMENTAL-EVIDENCE FOR A 2-STEP PROCESS IN THE AGGREGATION OF BETA-LACTOGLOBULIN AT PH 7

A two-step mechanism for beta-lactoglobulin aggregation at pH7 has bee n reported in the literature. The first aggregation step is difficult to characterise, as small particles are formed with a strong tendency to further associate in bigger aggregates. Experimental evidence for a two-step aggregation process, using scattering techniques and size ex clusion chromatography, is shown here. The effect of the ionic strengt h, the protein concentration and the heating temperature is discussed. The results show that the first step consists in the formation of sma ll globular aggregates, whose size are only weakly, if at all, influen ced by the parameters mentioned above.