Aggregates In The Protein Crystal Growth And Effect Of Thermal History

Biomolecules (e.g., proteins, nucleic acids and viruses ) with specific structuresplay important roles in many biological processes. To meet increasing demands ofprecise biomolecular 3D structures, especially protein structures by X-ray diffraction,it is more and more necessary to study their crystal growth. However, due to thedifficulties in protein crystal growth and less knowledge on biomolecular crystalgrowth mechanism, process of nucleic formation, basic thermodynamic and kineticparameters, it is very important to learn crystal growth mechanism. Laser LightScattering is an important tool of course as well as Atomic Force Microscopy(AFM).Laser light scattering, including two different methodologies, static lightscattering(SLS) and dynamic light scattering(DLS), is widely applied in research ofcrystal growth of macromolecule. SLS can be used to measure the osmotic secondvirial coefficient of protein solution. DLS is allowed for determination of thetranslational diffusion coefficient and can provide information about the size anddistribution of molecules in solution. It can also be used to separate nucleation andgrowth processes in protein crystallization and research aggregative behavior andkinetics of crystallization in macromolecular systems. So the dynamicalcrystallization processes may be controlled. In recent years, laser light scatteringinstrumentations has become continuously portable and miniaturization and thetechnique has grown gradually perfect. Not only it is applied in the basemeasurements, but also is used in the space experiments of protein crystal growth.With the high resolution and continuous images of cells and biomolecules,AFM has recently turned to be a powerful tool for the study of biomolecular shapes,conformations, behaviors, relationship between function and molecularconformation , and aggregations. With the applying of AFM, the surface morphologyof specific aggregates may be readily observed, potentially to sub-Angstromresolution.In this dissertation aggregates in protein solution have been mainly studied byDLS and AFM. The thesis is composed of three parts as follows.