title: A partially folded state of ovalbumin at low pH tends to aggregate.
abstract: At pH 2, ovalbumin retains native-like secondary structure as seen by far-UV CD and FTIR, but lacks well-defined tertiary structure as seen by the fluorescence and near-UV CD spectra. Addition of 20 mM Trifluoroacetic acid (TFA) or 30 mM Trichloroacetic acid (TCA) on acid-induced state results in protein aggregation. This aggregated state possesses extensive β-sheet structure as revealed by far-UV CD and FTIR spectroscopy. Furthermore, the aggregates exhibit decreased ANS fluorescence and increased thioflavin T fluorescence. The presence of aggregates was confirmed by size exclusion chromatography. Such a formation of β-sheet structure is found in the amyloid of a number of neurological diseases such as Alzheimer's and scrapie. Ovalbumin at low pH, in the presence of K(2)SO(4), exists in partially folded state characterized by native-like secondary structure and tertiary folds.
authors: Department of Biochemistry, Faculty of Life Science, AMU, Aligarh 202 002, India. aabgeenanaim@rediffmail.com
authors: Aabgeena
authors: A
authors: Naeem
authors: Taqi Ahmed
authors: TA
authors: Khan
authors: Mohammad
authors: M
authors: Muzaffar
authors: Saman
authors: S
authors: Ahmad
authors: M
authors: M
authors: Saleemuddin
mesh_terms: D000682:Amyloid / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D010047:Ovalbumin / Q000737:chemistry*; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary
chemical_list: D000682:Amyloid; D010047:Ovalbumin