UltraViolet-Circular dichroism (UV-CD), the differential absorption of left- and right-handed circularly polarized light in the UV range, is a highly sensitive spectroscopic method for the study of the conformations adopted by macromolecules in solution.
Although not able to provide detailed residue specific information, UV-CD measurements have two major advantages: they can be recorded on relatively small amounts of material (say 20 to 300 microliters) in various buffers (although phosphate buffers are prefered) and they allow to monitor structural changes. UV-CD is an optimal method:
- to estimate the protein secondary structure content and its variations with changing conditions or macromolecular mutation,
- to monitor molecule unfolding/refolding by temperature or denaturant,