Laser Optical Breakdown Modified Physical Properties of Lysozyme in Aqueous Solution

Abstract

Physico-chemical characteristics of optical-induced break-down depend weakly on the protein concentration. This factor distinguishes lysozyme from other aqueous solutions which contain objects with nano-size. The laser radiation of the lysozyme aqueous solution during different time periods shows patterns that are quite similar to the classical patterns. In this particular paper, it has been observed that the catalytic activity of lysozyme is decreasing after the laser radiation. The optical density of the protein solutions is increasing. The fluorescence intensity of the lysozyme solution is determined by the amino-acid residues. It decreases before and after the laser light influence. The position of the maximum of the excitation and emission did not change. The shape of the fluorescence signal on the 3D maps also does not change significantly. This observation suggests the degradation of the amino-acid residues. The viscosity and the pseudo plasticity of the lysozyme aqueous solutions increased. However, there is no massive damage of the polypeptide chain. On the contrary, the optical break-down shows the intensive forming of the lysozyme aggregates.