title: Analysing Cytochrome c Aggregation and Fibrillation upon Interaction with Acetonitrile: an in Vitro Study.
abstract: The propensity of native state to form aggregated and fibrillar assemblies is a hallmark of amyloidosis. Our study was focused at analyzing the aggregation and fibrillation tendency of cytochrome c in presence of an organic solvent i.e. acetonitrile. In vitro analysis revealed that the interaction of cytochrome c with acetonitrile facilitated the oligomerization of cytochrome c via the passage through an intermediate state which was obtained at 20 % v/v concentration of acetonitrile featured by a sharp hike in the ANS fluorescence intensity with a blue shift of 20 nm compared to the native state. Oligomers and fibrils were formed at 40 and 50 % v/v concentration respectively as indicated by a significant hike in the ThT fluorescence intensity, red shift of 55 nm in congo red binding assay and an increase in absorbance at 350 nm. They possess β-sheet structure as evident from appearance of peak at 217 nm. Finally, authenticity of oligomeric and fibrillar species was confirmed by TEM imaging which revealed bead like aggregates and a meshwork of thread like fibrils respectively. It could be suggested that the fibrillation of bovine cytchrome c could serve as a model protein to unravel the general aggregation and fibrillation pattern of heme proteins. Graphical abstract ᅟ.
authors.affiliation: Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, UP, 202 002, India.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Furkan
authors.affiliation: Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, UP, 202 002, India.
authors.forename: Naveed Ahmad
authors.initials: NA
authors.lastname: Fazili
authors.affiliation: Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, UP, 202 002, India.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Afsar
authors.affiliation: Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, UP, 202 002, India. aabgeenanaim@gmail.com.
authors.forename: Aabgeena
authors.initials: A
authors.lastname: Naeem
mesh_terms: D000097:Acetonitriles / Q000737:chemistry* / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D003224:Congo Red; D045304:Cytochromes c / Q000737:chemistry* / Q000378:metabolism*; D005453:Fluorescence; D006801:Humans; D007700:Kinetics; D008958:Models, Molecular; D011487:Protein Conformation; D055503:Protein Multimerization; D017385:Sequence Homology
chemical_list: D000097:Acetonitriles; D003224:Congo Red; D045304:Cytochromes c; C032159:acetonitrile
keywords: Acetonitrile; Amyloidosis; Cytochrome c; Heme proteins; Oligomers