Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

Browse

Filters

2025 - 20262

Settings

Access Right: Closed AccessSubject: search.filters.subject.Protein Conformation

Search Results

Now showing 1 - 2 of 2
  • Article
    Citation - WoS: 1
    Citation - Scopus: 1
    Biophysical Assessment of Protein Stability in Ethanol-Stressed Environments via UV Absorption and Fluorescence Spectroscopies
    (Elsevier, 2026) Akyuz, Ersed; Vorob'ev, Mikhail M.; Guler, Gunnur
    Maintaining the structure and functionality of proteins is crucial in applications ranging from food preservation to pharmaceutical formulation. Ethanol, while commonly used as a solvent and preservative, can induce structural changes in proteins depending on its concentration and the specific structure of the protein itself. This study investigates the structural effects of ethanol on three types of model proteins, namely bovine serum albumin (BSA), beta-Lactoglobulin (beta-Lg), and beta-Casein (beta-Cn), by using UV-Vis spectroscopy and fluorescence spectroscopy. The conformational responses of proteins in water-EtOH solutions of various ethanol concentrations (0-10 %, v/v) were analyzed through absorbance and emission spectral changes. At increasing ethanol concentration, UV absorption data showed distinct protein-dependent spectral changes. beta-Lg and beta-Cn exhibited strong hypochromism (an absorbance decrease of similar to 25 %) and red-shifting at 222 nm and 220 nm, respectively, indicating partial unfolding and solvent exposure of aromatic residues. BSA demonstrated subtle changes, and consistent quenching in fluorescence with a continuous blue-shifting to 330 nm, suggesting a moderate overall stability and local rearrangements in its structure. beta-Cn exhibited red-shifted fluorescence and quenching, reflecting its flexible, disordered structure and heterogeneous response to solvent conditions. Statistical analysis revealed that while fluorescence spectroscopy was highly sensitive to the intrinsic differences between proteins (p < 0.001), the ethanol-induced conformational changes were too subtle to be detected as a statistically significant treatment effect. The consistency of these trends indicates a rational underlying mechanism of interaction. This reflects the subtle nature of the effect at the tested concentrations rather than the absence of an effect. Moreover, these results unveil the protein-specific effects of ethanol and strongly emphasize the importance of solvent composition in maintaining protein integrity. Ethanol concentrations up to 5 % may offer protein stability whereas high ethanol levels (>= 5-10 %) promote structural perturbations. These results will be useful for both basic scientific research, such as biophysical studies and the advancement of optical techniques, and various industrial uses.
  • Article
    Citation - WoS: 3
    Citation - Scopus: 3
    Vibrational Spectroscopy in Plant-Based Protein Research: Quantification and Structural Analysis
    (Elsevier Science London, 2025) Cavdaroglu, Elif; Cavdaroglu, Cagri; Ozen, Banu
    Background: Plant-based proteins are gaining importance in food science, biotechnology, and human health as sustainable and nutrient-rich alternatives to animal-derived proteins. The rising demand for plant-based foods, driven by environmental concerns and dietary shifts, has intensified research into plant protein sources. Accurate determination of protein content and structure is essential for ensuring the nutritional quality, optimizing functionality, and maintaining product consistency. Traditional protein analysis methods, while effective, often require extensive sample preparation and time-consuming procedures. Vibrational spectroscopy, including Fourier-transform Infrared (FTIR), Near-Infrared (NIR), and Raman spectroscopy, offers a rapid, non-destructive, and efficient alternative for protein characterization in complex food matrices. Scope and approach: This review explores the application of vibrational spectroscopy in evaluating plant-based protein content and their secondary structure. It outlines the fundamental principles of FTIR, NIR, and Raman spectroscopy, emphasizing their advantages over conventional techniques. Key challenges, such as spectral overlap, water interference, and calibration requirements, are discussed alongside emerging solutions involving chemometric approaches, artificial intelligence, and hybrid analytical techniques. Key findings and conclusions: Vibrational spectroscopy provides precise protein quantification and structural analysis with minimal sample preparation. FTIR and Raman spectroscopy complement each other in protein conformation analysis, while NIR facilitates rapid bulk protein assessment. Advances in computational methods are enhancing spectral interpretation and accuracy. Integrating vibrational spectroscopy with complementary techniques can further improve protein characterization, supporting the development of high-quality, sustainable plant-based protein sources for food and biotechnology applications.