FT-Raman Spectroscopy as a Tool to Study the Secondary Structures of Wheat Gliadin Proteins

Raman spectroscopy is a useful method in biological, biomedical, food, and agricultural studies, allowing the simultaneous examination of various chemical compounds and evaluation of molecular changes occurring in tested objects. The purpose of our research was to explain how the elimination of ω-fractions from the wheat gliadin complex influences the secondary structures of the remaining αβγ-gliadins. To this aim, we analyzed the endosperm of wheat kernels as well as gliadin proteins extracted from two winter wheat genotypes: wasko.gl+ (control genotype containing the full set of gliadins) and wasko.gl− (modified genotype lacking all ω-gliadins). Based on the decomposition of the amide I band, we observed a moderate increase in β-forms (sheets and turns) at the expense of α-helical and random coil structures for gliadins isolated from the flour of the wasko.gl− line. Since ω-gliadins contain no cysteine residues, they do not participate in the formation of the disulfide bridges that stabilize the protein structure. However, they can interact with other proteins via weak, low-energetic hydrogen bonds. We conclude that the elimination of ω-fractions from the gliadin complex causes minor modifications in secondary structures of the remaining gliadin proteins. In our opinion, these small, structural changes of proteins may lead to alterations in gliadin allergenicity.

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FT-Raman signatures of genomic DNA from plant tissues

Spectroscopy An International Journal ◽

10.1155/2009/131859 ◽

2009 ◽

Vol 23 (2) ◽

pp. 59-70 ◽

Cited By ~ 15

Author(s):

Cristina M. Muntean ◽

Adela Halmagyi ◽

Mircea D. Puia ◽

Ioana Pavel

Keyword(s):

Raman Spectroscopy ◽

Structural Changes ◽

Plant Tissues ◽

Dendranthema Grandiflora ◽

Drosera Rotundifolia ◽

Ligand Interactions ◽

Ft Raman Spectroscopy ◽

Leaf Tissues ◽

Genomic Dnas ◽

Ft Raman

The vibrational spectra of eight genomic DNAs from leaf tissues (sword fern (Nephrolepis exaltataL.), chrysanthemum (Dendranthema grandifloraRamat.), redwood (Sequoia sempervirensD. Don. Endl.), orchids (Cymbidium × hybrida), common sundew (Drosera rotundifoliaL.), potato (Solanum tuberosumL.) and scopolia (Scopolia carniolicaJacq.)) have been analyzed using FT-Raman spectroscopy, in the wavenumber range 500–1800 cm–1.FT-Raman signatures, spectroscopic assignments and structural interpretations for these plant genomic DNAs are reported. Spectral differences among two genomic DNAs, independently extracted from chrysanthemum leaves, are to be observed between 1000–1200 cm–1. Besides, similarities in the FT-Raman spectra of genomic DNAs from potato and scopolia leaves, respectively, have been found. This might be explained by their belonging to the same family (Solanaceae). Other spectral differences among genomic plant DNAs have also been observed.These findings demonstrate that Raman spectroscopy may be exploited to distinguish different plant genomic DNAs.The present study provides a basis for future use of Raman spectroscopy to analyze specific plant DNA–ligand interactions or DNA structural changes induced by plants' stress conditions associated with their natural environment.

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On-Line Monitoring of Airborne Chemistry in Levitated Nanodroplets: In Situ Synthesis and Application of SERS-Active Ag−Sols for Trace Analysis by FT-Raman Spectroscopy

Analytical Chemistry ◽

10.1021/ac026308l ◽

2003 ◽

Vol 75 (9) ◽

pp. 2166-2171 ◽

Cited By ~ 48

Author(s):

Nicolae Leopold ◽

Michael Haberkorn ◽

Thomas Laurell ◽

Johan Nilsson ◽

Josefa R. Baena ◽

...

Keyword(s):

Raman Spectroscopy ◽

Trace Analysis ◽

In Situ Synthesis ◽

Ft Raman Spectroscopy ◽

On Line ◽

Ft Raman

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Application of FT-Raman spectroscopy to the study of selected organometallic complexes and proteins

Canadian Journal of Chemistry ◽

10.1139/v90-185 ◽

1990 ◽

Vol 68 (7) ◽

pp. 1196-1200 ◽

Cited By ~ 7

Author(s):

Steven M. Barnett ◽

François Dicaire ◽

Ashraf A. Ismail

Keyword(s):

Raman Spectroscopy ◽

Near Infrared ◽

Metal Carbonyl ◽

Protein A ◽

Organometallic Complexes ◽

Laser Source ◽

Chromium Tricarbonyl ◽

Ft Raman Spectroscopy ◽

Arene Chromium Tricarbonyl ◽

Ft Raman

The study of colored organometallic complexes by dispersive Raman spectroscopy has been limited due to fluorescence or photodecomposition caused by the visible laser used as the excitation source. As a solution to this problem, FT-Raman spectroscopy with a near-infrared laser source has been useful in lowering fluorescence or photolysis in these samples. To investigate the utility of this technique, we have obtained and assigned the FT-Raman spectra of a series of arene chromium tricarbonyl complexes and of cyclopentadienyl manganese tricarbonyl. Some bands previously unobserved by dispersive Raman spectroscopy were seen, including a band assigned to a 13CO satellite in the spectrum of methylbenzoate chromium tricarbonyl. In addition, FT-Raman data for bovine serum albumin (BSA) and Protein-A are presented. Keywords: FT-Raman spectroscopy, metal carbonyl, proteins, organometallics, near infrared.

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