Infrared Spectroscopy of Proteins

Abstract

Infrared spectroscopy provides molecular information in systems that range from the level of peptides, isolate proteins and enzymes, to even more complex systems such as peptide–protein complexes and membrane‐bound proteins. The information may be a global one such as the secondary structure composition of a protein, or it may be highly specific such as the alteration of individual vibrating bonds in an enzyme. Furthermore, the structural information is not restricted to a static picture, but can also be obtained at high time resolution to allow true structure–function correlation. Illustrative examples are given to demonstrate the sort of information, which infrared techniques can provide and how this information can be extracted from the experimental data. In addition, strengths and limitations of the infrared approach are discussed. This should help the reader to evaluate whether a particular system is appropriate for study by infrared spectroscopy, and what specific advantages are gained when applying infrared techniques.

Solid-phase extraction of tanshinones from Salvia Miltiorrhiza Bunge using ionic liquid-modified silica sorbents

“…The spectra of ionic liquid-modified silica exhibited an inconspicuous peak at the wavelength of 1575 cm −1 in Fig. 3 and the finger print region of the amide bands was from 1500 to 1600 cm −1 [29,30]. This means some C-N groups had interacted with the commercial silica.…”

Advanced characterization of immobilized enzymes as heterogeneous biocatalysts

“…The most widely used method is Fourier transformed infrared spectroscopy (FTIR) [92,93]. Changes in the protein's relative composition in secondary structure and also in the tertiary fold on immobilization can be monitored using FTIR, as shown in Table 3.…”

Research on the adsorption property of supported ionic liquids for ferulic acid, caffeic acid and salicylic acid

“…The spectra of quinoline SILs exhibited a characteristic absorption peak at the wavelength of 1530 cm −1 , 1527 cm −1 and 1567 cm −1 and the finger print region of C-N vibration was from 1500 to 1600 cm −1 [15]. This means that some C-N groups had interacted with the commercial silica.…”