title: Oligomers, protofibrils and amyloid fibrils from recombinant human lysozyme (rHL): fibrillation process and cytotoxicity evaluation for ARPE-19 cell line.
abstract: Amyloid-associated diseases, such Alzheimer's, Huntington's, Parkinson's, and type II diabetes, are related to protein misfolding and aggregation. Herein, the time evolution of scattered light intensity, hydrophobic properties, and conformational changes during fibrillation processes of rHL solutions at 55 °C and pH 2.0 were used to monitor the aggregation process of recombinant human lysozyme (rHL). Dynamic light scattering (DLS), thioflavin T (ThT) fluorescence, and surface tension (ST) at the air-water interface were used to analyze the hydrophobic properties of pre-amyloid aggregates involved in the fibrillation process of rHL to find a correlation between the hydrophobic character of oligomers, protofibrils and amyloid aggregates with the gain in cross-β-sheet structure, depending on the increase in the incubation periods. The ability of the different aggregates of rHL isolated during the fibrillation process to be adsorbed at the air-water interface can provide important information about the hydrophobic properties of the protein, which can be related to changes in the secondary structure of rHL, resulting in cytotoxic or non-cytotoxic species. Thus, we evaluated the cytotoxic effect of oligomers, protofibrils and amyloid fibrils on the cell line ARPE-19 using the MTT reduction test. The more cytotoxic protein species arose after a 600-min incubation time, suggesting that the hydrophobic character of pre-amyloid fibrils, in addition to the high prevalence of the cross-β-sheet conformation, can become toxic for the cell line ARPE-19.
authors.affiliation: Departamento de Física, Universidad de Sonora, Rosales y Transversal, 83000 Hermosillo, Sonora, Mexico.
authors.forename: Eva D
authors.initials: ED
authors.lastname: Ruiz
authors.affiliation: Departamento de Física, Universidad de Sonora, Rosales y Transversal, 83000 Hermosillo, Sonora, Mexico.
authors.forename: Mario
authors.initials: M
authors.lastname: Almada
authors.affiliation: Departamento de Investigaciones Científicas y Tecnológicas, Universidad de Sonora, Rosales y Transversal, 83000 Hermosillo, Sonora, Mexico.
authors.forename: María G
authors.initials: MG
authors.lastname: Burboa
authors.affiliation: Departamento de Física de la Materia Condensada, Facultad de Física, Universidad de Santiago de Compostela, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Taboada
authors.affiliation: Departamento de Física de la Materia Condensada, Facultad de Física, Universidad de Santiago de Compostela, Spain.
authors.forename: Víctor
authors.initials: V
authors.lastname: Mosquera
authors.affiliation: Departamento de Física, Universidad de Sonora, Rosales y Transversal, 83000 Hermosillo, Sonora, Mexico.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Valdez
authors.affiliation: Departamento de Física, Universidad de Sonora, Rosales y Transversal, 83000 Hermosillo, Sonora, Mexico. Electronic address: josue.juarez@correo.fisica.uson.mx.
authors.forename: Josué
authors.initials: J
authors.lastname: Juárez
mesh_terms: D000682:Amyloid / Q000737:chemistry* / Q000378:metabolism / Q000633:toxicity*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D009113:Muramidase / Q000737:chemistry* / Q000378:metabolism / Q000633:toxicity; D010316:Particle Size; D066263:Protein Aggregation, Pathological; D011994:Recombinant Proteins / Q000737:chemistry* / Q000378:metabolism / Q000633:toxicity; D013329:Structure-Activity Relationship; D013499:Surface Properties
chemical_list: D000682:Amyloid; D011994:Recombinant Proteins; D009113:Muramidase
keywords: ARPE-19; Amyloid fibrils; Oligomers; Protofibrils; Recombinant human lysozyme