Institution: | 1. Departamento de Química Analítica, Química Física e Ingeniería Química, Universidad de Alcalá, Ctra. Madrid-Barcelona, Km. 33.600, 28871, Alcalá de Henares, Madrid, Spain;2. Instituto de Investigación Química “Andrés M. del Río”, Universidad de Alcalá, Ctra. Madrid-Barcelona, Km. 33.600, 28871, Alcalá de Henares, Madrid, Spain;3. Departamento de Química Orgánica y Química Inorgánica, Universidad de Alcalá, Ctra. Madrid-Barcelona, Km. 33.600, 28871, Alcalá de Henares, Madrid, Spain;4. Networking Research Center for Bioengineering, Biomaterials and Nanomedicine, (CIBER-BBN), Spain;5. Instituto Ramón y Cajal de Investigación Sanitaria, IRYCIS, Spain;1. Department of Chemistry, Liaocheng University, Liaocheng 252059, China;2. Key Laboratory of Food Nutrition and Safety, Ministry of Education of China, Tianjin University of Science and Technology, Tianjin 300457, China;3. Laboratoire d''Electrochimie Physique et Analytique, Station 6, Ecole Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland |
Abstract: | Protein misfolding can facilitate a protein damaging process and makes it susceptible to a series of events such as unfolding, adduct formation, oligomerization, or aggregation. Loss of a protein’s native structure may result in its biological malfunction and/or cellular toxicity that could cause associated diseases. Several factors were identified for causing structural changes of a protein, however quinone-induced protein modifications received very little attention whether for amyloidal or non-amyloidal proteins. In this paper, we report our investigation on lysozyme modifications upon treatment with selected benzoquinones (BQs), utilizing fluorescence spectroscopy including anisotropy determination, UV–Vis spectroscopy, and SDS-PAGE. Lysozyme was reacted with substituted BQs in order to examine substituent effects on protein modifications. In addition, we evaluated lysozyme modifications induced by 1,4-benzoquinone in concentration-, pH-, temperature-, and time-dependent studies. Our study shows that all BQs can readily modify lysozyme in a complex manner through adduct formation, oligomerization, polymeric aggregation, and/or fibrilization. Electrochemical properties of selected BQs were monitored using cyclic voltammetry in phosphate buffered aqueous solution, and it was found that quinone reduction potentials correlate well with their reactivity trend toward lysozyme. |