title: Effect of trifluoroethanol on native and acid-induced states of glucose oxidase from Aspergillus niger.
abstract: We have studied the effect of trifluoroethanol (TFE) on the native (pH 7.0), acid unfolded (pH 2.6), and molten globule (pH 1.4) states of glucose oxidase (GOX) by circular dichroism and fluorescence spectroscopy. In the presence of 50% TFE, at pH 7.0 and 2.6, GOX exhibited a transition from native coiled-coil and acid unfolded state to non-associating alpha-helical state. Interestingly, at pH 1.4, 15% TFE induced the formation of beta-structured intermediate by loss of 1-anilino-8-naphthalenesulfonate binding site and almost all tertiary contacts. The beta-structured intermediate converted into open helical conformation on further addition of TFE.
authors.affiliation: Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, 202002, India. rizwanhkhan@hotmail.com.
authors.forename: B
authors.initials: B
authors.lastname: Ahmad
authors.forename: S K
authors.initials: SK
authors.lastname: Haq
authors.forename: A
authors.initials: A
authors.lastname: Varshney
authors.forename: A A
authors.initials: AA
authors.lastname: Moosavi-Movahedi
authors.forename: R H
authors.initials: RH
authors.lastname: Khan
mesh_terms: D000817:Anilino Naphthalenesulfonates / Q000737:chemistry; D001234:Aspergillus niger / Q000201:enzymology*; D001665:Binding Sites; D002942:Circular Dichroism; D005949:Glucose Oxidase / Q000737:chemistry* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D011489:Protein Denaturation; D017433:Protein Structure, Secondary; D013050:Spectrometry, Fluorescence; D014270:Trifluoroethanol / Q000494:pharmacology*
chemical_list: D000817:Anilino Naphthalenesulfonates; C027132:1-anilino-8-naphthalenesulfonate; D014270:Trifluoroethanol; D005949:Glucose Oxidase