Determining Protein Secondary Structure with Spectrum™ 100

In this application note by PerkinElmer, information about BSA protein secondary structure is determined based on Amide-1 and Amide-2 bands, using the region 1800 to 1400cm^-1 after subtraction of the water absorption. The secondary structure is analyzed as a mixture of different amounts of various sub-structures such as α-helix and β-sheet, each of which has characteristic absorptions. In curve-fitting and deconvolution approaches the amide-1 band is analysed explicitly as the superposition of such bands. Although crystallography and NMR are the primary tools for determining geometrical protein structures there are significant limitations in the range of proteins that these techniques can address. FT-IR gives less detailed information but it has some important advantages. It can be applied to any protein, it requires a relatively small sample, and the measurements can be made in solution.