Circular Dichroism Spectropolarimeter (CD)
CD measures difference in absorption of of right- and left-circularly polarized light by a sample. It equipped with rectangular cuvette holder with temperature controlled by Peltier element. Cuvettes of pathlength range 0.1 – 10 mm are available.
- Protein secondary structure assessment. Protein CD spectra in far UV (180 – 250 nm) can be used to asses content of secondary structures by comparison to external libraries of CD spectra for proteins with known secondary structure contents.
- Proteins and nucleic acids stability. Changes in CD spectra induced by chemical denaturants or temperature increase allows studies on structure destabilization. The same method can be applied for nucleic acids (but no reference spectra libraries exist).
- Structural changes induced by ligand binding. Comparison of ligand-free and ligand-bound protein (or nucleic acid) can be used to infer information about conformational changes induced by ligand binding.
Protein analysis. A. Overlay of CD spectra of proteins with different secondary structure content (BA Wallace, 2019). B Overlay of BSA and lysozyme spectra.