Lysozyme Aggregation Studied by Light Scattering. II. Variations of Protein Concentration

Abstract

Static and dynamic light scattering have been employed to investigate the behaviour of nucleating lysozyme solutions in the range between 0.34 and 3.08mM. Preselected concentrations of NaC1 and (NH4)2SO 4 have been used to screen the repulsive Coulombic interactions and trigger aggregation. Initially, massfractals undergoing diffusion limited-like aggregation coexist with monomers or small lysozyme oligomers. The growth kinetics of the fractals deliver observables that exhibit distinct tendencies when examined as a function of lysozyme concentration. The behaviour of the observables changes drastically around 2.0mM lysozyme. Static light scattering experiments revealed progressive restructuring or growth of compact structures at later stages of the aggregation. Based on the correlations between the observables an attempt is made to predict whether the examined solutions will crystallize or not. A tentative scheme, involving the most prominent structures observed in nucleating lysozyme solutions, is discussed.

Differential pathways in oxy and deoxy HbC aggregation/crystallization

“…Depressions have been observed during the growth of lysozyme crystals 37, 38. Their formation has been associated with transport‐induced lower supersaturations at the facet centers that lead to buckling of the center of the face and further deterioration of the nutrition of this area, which in turn lowers the growth rate in the face center 35, 37–43. Similarly, amorphous aggregates sometimes appeared with similar depressions (Fig.…”

“…It is unlikely that this is a rearrangement, such as a solid‐phase transition within the amorphous aggregate, to form a crystalline lattice. This would require a highly unusual solid‐solid phase transition that has not been observed for proteins 34, 35. The observation of a crystalline phase forming on top of an amorphous aggregate is very interesting in that it may correlate with the often‐sited appearance of crystals that do not diffract 27…”

Detection of protein aggregation with a Bloch surface wave based sensor

“…The kinetics of amyloid fibril formation is a function of the protein concentration. Low protein concentration slow down the aggregation kinetics substantially, which explains the proportionally reduced shift [24].…”

Dense liquid droplets as a step source for the crystallization of lumazine synthase

“…The theory, technique and methods of particle size distributions from the analysis of ACF have been described in detail in Refs. [23,24].…”