title: Synthetic food additive dye "Tartrazine" triggers amorphous aggregation in cationic myoglobin.
abstract: Protein aggregation, a characteristic of several neurodegenerative diseases, displays vast conformational diversity from amorphous to amyloid-like aggregates. In this study, we have explored the interaction of tartrazine with myoglobin protein at two different pHs (7.4 and 2.0). We have utilized various spectroscopic techniques (turbidity, Rayleigh light scattering (RLS), intrinsic fluorescence, Congo Red and far-UV CD) along with microscopy techniques i.e. atomic force microscopy (AFM) and transmission electron microscopy (TEM) to characterize the tartrazine-induced aggregation in myoglobin. The results showed that higher concentrations of tartrazine (2.0-10.0mM) induced amorphous aggregation in myoglobin at pH 2.0 via electrostatic interactions. However, tartrazine was not able to induce aggregation in myoglobin at pH 7.4; because of strong electrostatic repulsion between myoglobin and tartrazine at this pH. The tartrazine-induced amorphous aggregation process is kinetically very fast, and aggregation occurred without the formation of a nucleus. These results proposed that the electrostatic interaction is responsible for tartrazine-induced amorphous aggregation. This study may help in the understanding of mechanistic insight of aggregation by tartrazine.
authors.affiliation: Department of Food Science and Nutrition, Faculty of Food and Agricultural Sciences, King Saud University, 2460, Riyadh, 11451, Saudi Arabia. Electronic address: nalshabib@ksu.edu.
authors.forename: Nasser Abdulatif
authors.initials: NA
authors.lastname: Al-Shabib
authors.affiliation: Department of Food Science and Nutrition, Faculty of Food and Agricultural Sciences, King Saud University, 2460, Riyadh, 11451, Saudi Arabia.
authors.forename: Javed Masood
authors.initials: JM
authors.lastname: Khan
authors.affiliation: Protein Research Chair, Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Mohd Shahnawaz
authors.initials: MS
authors.lastname: Khan
authors.affiliation: Surfactant Research Chair, Department of Chemistry, King Saud University, PO Box-2455, Riyadh, 11451, Saudi Arabia.
authors.forename: Mohd Sajid
authors.initials: MS
authors.lastname: Ali
authors.affiliation: Protein Research Chair, Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Abdulrahman M
authors.initials: AM
authors.lastname: Al-Senaidy
authors.affiliation: Department of Pharmaceutics, College of Pharmacy, King Saud University, Saudi Arabia.
authors.forename: Mohammad A
authors.initials: MA
authors.lastname: Alsenaidy
authors.affiliation: Department of Food Science and Nutrition, Faculty of Food and Agricultural Sciences, King Saud University, 2460, Riyadh, 11451, Saudi Arabia.
authors.forename: Fohad Mabood
authors.initials: FM
authors.lastname: Husain
authors.affiliation: Surfactant Research Chair, Department of Chemistry, King Saud University, PO Box-2455, Riyadh, 11451, Saudi Arabia.
authors.forename: Hamad A
authors.initials: HA
authors.lastname: Al-Lohedan
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D005505:Food Coloring Agents / Q000494:pharmacology*; D006736:Horses; D007700:Kinetics; D008958:Models, Molecular; D009211:Myoglobin / Q000737:chemistry*; D066329:Protein Aggregates / Q000187:drug effects*; D017433:Protein Structure, Secondary / Q000187:drug effects; D017434:Protein Structure, Tertiary / Q000187:drug effects; D013645:Tartrazine / Q000494:pharmacology*
chemical_list: D005505:Food Coloring Agents; D009211:Myoglobin; D066329:Protein Aggregates; D013645:Tartrazine
keywords: Amorphous aggregates; Congo Red; Food additive dye; Myoglobin; Protein aggregation; Tartrazine; pH