Nonreciprocal XeCl laser-induced aggregation of β -crystallins in water solution

Evgeny Chelnokov,Natalia Sapogova,Mikhail Ostrovsky,Nikita Bityurin,Lev Soustov

doi:10.1364/oe.16.018798

Abstract

The aggregation of a beta-crystallin water solution exposed to XeCl laser radiation demonstrates the dependence of scattering-exposure curve (scattering versus exposure) on laser intensity. The main features of this dependence can be understood by the relaxation of a partly denaturated state of a protein within some finite relaxation time. These photoactivated states originate from the absorption of UV photons. Two partly denaturated (photoactivated) monomers, as well as other aggregates, can aggregate, giving rise to sharply increasing probe light scattering after some lag time of irradiation.

Highlights

Laser irradiation of materials can result in significant changes in their optical properties
Despite the fact that there are some comprehensive studies on the kinetics of crystallin aggregation produced by irradiation with UV lamps, very few papers are devoted to laserinduced crystallin aggregation [5,6,7]
The scattering of the sample abruptly increases. Reciprocity suggests that this lag period is inversely proportional to the light intensity or that lag exposure in the scattering-exposure curve should not depend on the light intensity

Summary

Introduction

Laser irradiation of materials can result in significant changes in their optical properties. One of the important examples is the aggregation of water-soluble proteins with UV laser light from a XeCl excimer laser (308 nm). This phenomenon is currently being investigated to elucidate cataract development. The molecular mechanisms of the origin and development of certain forms of cataracts, including photocataractogenesis, are based on the degradation and aggregation of the main water-soluble proteins in the eye lens (α-, β-, and γ-crystallins) [1,2,3]. The scattering of the sample abruptly increases Reciprocity suggests that this lag period is inversely proportional to the light intensity or that lag exposure in the scattering-exposure curve should not depend on the light intensity

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