Precrystallization structures in supersaturated lysozyme solutions studied by dynamic light scattering and scanning force microscopy

Abstract

A comparitive study of the nanostructure evolving during aggregation of hen-egg white lysozyme in supersaturated solution was carried out by dynamic light scattering ͑DLS͒ and scanning force microscopy ͑SFM͒. Lysozyme aggregate ͑cluster͒ formation was observed in solution in the presence of NaCl, ͑NH 4 ͒ 2 SO 4 , and NaNO 3 as precipitating agents. The growth kinetics were examined by DLS and revealed fractal growth of the clusters with a fractal dimension of 1.8 obtained independently of the type of inert salt. Such behavior is typical for diffusion-limited cluster-cluster ͑DLCA͒ aggregation. Initial lysozyme cluster sizes were in the range of 12-35 nm. SFM images of individual lysozyme clusters at the liquid-solid interface were obtained in the presence of NaCl and NaNO 3 under crystallization conditions, and revealed cluster sizes in agreement with those determined by DLS. Extended domains of smaller sized clusters appeared on the mica surface after subjecting supersaturated lysozyme solutions to a dialysis step. The feasibility of DLS and SFM for monitoring the nano-and mesoscopic morphology of lysozyme aggregates in supersatured solutions and at the solid-liquid interface is discussed.

Time-Resolved Small-Angle Static Light Scattering on Lysozyme during Nucleation and Growth

“…For lysozyme under crystallization conditions, this issue is, however, still under investigation. 51, 58 An obvious point emerging from the present and other studies is that detailed knowledge of the nucleation and aggregation events over wide spatiotemporal scales is necessary. The present work should be understood only as an attempt toward a better comprehension of the events taking place during biomolecular crystallization.…”

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

“…This postulate is supported only by few experimental studies (Brune, Romainczyk, R6der & Kern, 1994; Dokter, van Garderen, Beelten, van Santen & Bras, 1995) and for nucleating lysozyme solutions has been investigated by atomic force microscopy in solution (Schaper, Georgalis, Umbach, Raptis & Saenger, 1997).…”

Generation of nanostructures of mica supported lysozyme molecules in aqueous solution by atomic force microscopy

“…If those linelike pattern are fused to conducting nanoparticles (nanogold) the method could be applied in molecular electronics to form conductors with dimensions in the nanometer range [44]. Furthermore, it could be speculated whether formation of 3D-aggregates could be used as nucleation sites for protein crystal nucleation [10,45].…”

“…Spectroscopic methods are used for achieving the amount of adsorbed lysozyme depending on ionic strength [8]. The scanning tunneling microscope and atomic force microscope (AFM) were applied to gain information about the surface distribution of spontaneously adsorbed lysozyme on solid supports [9][10][11]. The most important driving force for lysozyme adsorption and desorption were theoretically described as van der Waals and electrostatic interaction [12][13][14].…”