Fourier transform infrared spectroscopy protein secondary structures

Prestrelski SJ, Byler DM, Liebman MN. Generation of a substructure library for the description and classification of protein secondary structure. II. Application to spectrastructure correlations in Fourier transform infrared spectroscopy. Proteins 1992 14 440-450. 

The conformational changes which have been described so far are probably all relatively small local changes in the structure of H,K-ATPase. This has been confirmed by Mitchell et al. [101] who demonstrated by Fourier transform infrared spectroscopy that a gross change in the protein secondary structure does not occur upon a conformational change from Ei to 3. Circular dichroism measurements, however [102,103], indicated an increase in a-helical structure upon addition of ATP to H,K-ATPase in the presence of Mg and... 

Vandenbussche G, Clercx A, Clercx M, et al. Secondary structure and orientation of the surfactant protein SP-B in a lipid environment. A Fourier transform infrared spectroscopy study. Biochemistry 1992 31(38) 9169-9176. 

The wavelengths of IR absorption bands are characteristic of specific types of chemical bonds. In the past infrared had little application in protein analysis due to instrumentation and interpretation limitations. The development of Fourier transform infrared spectroscopy (FUR) makes it possible to characterize proteins using IR techniques (Surewicz et al. 1993). Several IR absorption regions are important for protein analysis. The amide I groups in proteins have a vibration absorption frequency of 1630-1670 cm. Secondary structures of proteins such as alpha(a)-helix and beta(P)-sheet have amide absorptions of 1645-1660 cm-1 and 1665-1680 cm, respectively. Random coil has absorptions in the range of 1660-1670 cm These characterization criteria come from studies of model polypeptides with known secondary structures. Thus, FTIR is useful in conformational analysis of peptides and proteins (Arrondo et al. 1993). 

Surewicz, W.K., Mantsch, H.H., Chapman, D. (1993). Determination of protein secondary structure by Fourier transform infrared spectroscopy A critical assessment. Biochemistry, 32, 389-394. 

The secondary structure of proteins may also be assessed using vibrational spectroscopy, fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy both provide information on the secondary structure of proteins. The bulk of the literature using vibrational spectroscopy to study protein structure has involved the use of FTIR. Water produces vibrational bands that interfere with the bands associated with proteins. For this reason, most of the FTIR literature focuses on the use of this technique to assess structure in the solid state or in the presence of non-aqueous environments. Recently, differential FTIR has been used in which a water background is subtracted from the FTIR spectrum. This workaround is limited to solutions containing relatively high protein concentrations. 

The secondary structure of the 33 kDa protein in solution has been examined by spectroscopic studies. Fourier transform infrared spectroscopy has indicated that the 33 kDa protein is composed predominandy of P structure " a conclusion reinforced by circular dichroism measurements in the UV region.The 33 kDa protein has been proposed to be either a natively... 

Zhang H, Ishikawa Y, Yamamoto Y et al. Secondary structure and thermal stability of the extrinsic 23 kDa protein of photosystem II studied by Fourier transform infrared spectroscopy. FEBS Lett... 

This process was confirmed by both circular dichroism and Fourier transform infrared spectroscopy, suggesting tirat a-synuclein has a slightly collapsed conformation, with 14% of its secondary structure corresponding to tums. In line with these data, the determination of the hydrodynamic dimensions of a-synuclein revealed that the protein was indeed... 

Fourier transform infrared spectroscopy (FTIR) is a powerful tool used to monitor changes in protein and polypeptide secondary structure during processing. After exposure of a protein to infrared light, its secondary structure can be determined from the spectra obtained from the absorption of different wavelengths corresponding to specific vibration frequencies of the amide bonds (Jackson and Mantsch, 1995a). 

The availability of the purified transporter in large quantity has enabled investigation of its secondary structure by biophysical techniques. Comparison of the circular dichroism (CD) spectrum of the transporter in lipid vesicles with the CD spectra of water-soluble proteins of known structure indicated the presence of approximately 82% a-helix, 10% ) -turns and 8% other random coil structure [97]. No / -sheet structure was detected either in this study or in a study of the protein by the same group using polarized Fourier transform infrared (FTIR) spectroscopy [98]. In our laboratory FTIR spectroscopy of the transporter has similarly revealed that... 

Fourier transform infrared/photoacoustic spectroscopy (FT-IR/PAS) can be used to evaluate the secondary structure of proteins, as demonstrated by experiments on concanavalin A, hemoglobin, lysozyme, and trypsin, four proteins having different distributions of secondary... 

Following successful recovery of peptide/protein molecule from the microspheres, a simple spectrophotometric method does not always allow discrimination between the monomeric protein form and its aggregates. However, HPLC might separate these species and thus provides more accurate qualitative data [96], But HPLC cannot quantify exclusively the amount of active protein antigen, as is the case with ELISA techniques [97], Nowadays, Fourier transform infrared (FTIR) spectroscopy has become a popular, noninvasive method, as it is able to characterize the secondary structure of entrapped proteins [26, 95, 98-101], Only recently, the integrity of their primary structure was evaluated, thanks to a new matrix-assisted laser... 

Fourier-transform infrared (FTIR) spectroscopy is particularly useful for probing the structures of membrane proteins [3, 23]. This technique can be used to study the secondary structures of proteins, both in their native environment as well as after reconstitution into model membranes. Myelin basic protein (MBP) is a major protein of the nervous system and has been studied by using FTIR spectroscopy in both aqueous solution and after reconstitution in myelin lipids [24]. The amide I band of MBP in D2O solution (deconvolved and curve-fitted) is... 

Fourier-transformed infrared (FTIR) is another excellent method to study protein folding. Unlike the well-known use of FTIR as a method for the identification of functional groups, in terms of protein structure this method allows the determination of secondary structure. The frequency of vibration of the amide I band of the peptide chain (1500-1600 cm M heavily depends on the structure of the protein. FTIR has the advantage of being more sensitive for the study of proteins that contain (3-sheet elements as compared to CD. Furthermore, since FTIR spectroscopy can be applied to solids also, it allows the structural analysis of aggregated protein deposits. The availability of the rapid step-scan method for FTIR is also very useful for the study of rapid folding reactions (see Vibrational Spectroscopy). 

Raman spectroscopy is a vibrational spectroscopic technique which can be a useful probe of protein structure, since both intensity and frequency of vibrational motions of the amino acid side chains or polypeptide backbone are sensitive to chemical changes and the microenvironment around the functional groups. Thus, it can monitor changes related to tertiary structure as well as secondary structure of proteins. An important advantage of this technique is its versatility in application to samples which may be in solution or solid, clear or turbid, in aqueous or organic solvent. Since the concentration of proteins typically found in food systems is high, the classical dispersive method based on visible laser Raman spectroscopy, as well as the newer technique known as Fourier-transform Raman spectroscopy which utilizes near-infrared excitation, are more suitable to study food proteins (Li-Chan et aL, 1994). In contrast the technique based on ultraviolet excitation, known as resonance Raman spectroscopy, is more commonly used to study dilute protein solutions. 

Kumosinski, T.F. Farrell, H.M., Jr. Determination of the global secondary structure of proteins by Fourier transform infrared (FTIR) spectroscopy. Trends Food Sci. Technol. 1993, 4, 169-175. 

Applying attenuated total reflection Fourier transform infrared and total internal reflection fluorescence spectroscopy, the same group studied the secondary structure and aggregation properties of different proteins that are adsorbed onto planar PAA brushes (Hollmann, Steitz, Czeslik, 2008 Reichhart Czeslik, 2008). They found... 

Because neither PrP" nor PrP " " could be crystallized, it was not possible to establish the 3D structure of these proteins by X-ray crystallography To circumvent this xmfavorable situation, Prusiner used circular dichroism and Fourier transformed infrared (FTIR) spectroscopy, both techniques that allow determination of the respective percentages of the secondary structures (a, (3, and turns) in a peptide or a protein. Applied to PrP and PrP samples, these spectroscopic approaches definitely demonstrated that both isoforms have a distinct 3D structure. In a seminal article published in 1993, the Prusiner s group established that PrP is chiefly an a-helical protein (43% of a-helix structure) with few -structures (3%). In contrast, PrP has less a-helix (30%) but has gained a high percentage of -structures (43%). 

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