PROTEIN-STRUCTURE FROM LINEAR DICHROISM SPECTROSCOPY AND TRANSIENT ELECTRIC BIREFRINGENCE

This paper discusses two less well-known techniques for studying protein structures in solution, linear dichroism (LD) spectroscopy and electric field induced transient birefringence (ETB). From the former, information on the orientation of chromophoric groups in molecules, on molecular characteristics such as shape, size, and electronic properties, and on binding parameters in molecular complexes, can be determined. From ETB hydrodynamic and electronic parameters, aggregational state, and intramolecular flexibility can be monitored. Both techniques are comparatively fast, and use relatively small quanties (0.2-1 mg) of protein at low concentration. After a general description of the principles of the techniques, their application for the study of a specific lens-protein, alpha-crystallin, is discussed in detail.