Alcohol-induced structural transitions in the acid-denatured Bacillus licheniformis α-amylase
Document Type
Article
Publication Date
1-1-2017
Abstract
Alcohol-induced structural changes in the acid-denatured Bacillus licheniformis α-amylase (BLA) at pH 2.0 were studied by far-ultra violet circular dichroism, intrinsic, three-dimensional and 8-anilino-1-naphthalene sulfonic acid (ANS) fluorescence, acrylamide quenching and thermal denaturation. All the alcohols used in this study produced partial refolding in the acid-denatured BLA as evident from the increased mean residue ellipticity at 222 nm, increased intrinsic fluorescence and decreased ANS fluorescence. The order of effectiveness of these alcohols to induce a partially folded state of BLA was found to be: 2,2,2-trifluoroethanol/tert-butanol > 1-propanol/2-propanol > 2-chloroethanol > ethanol > methanol. Three-dimensional fluorescence and acrylamide quenching results obtained in the presence of 5.5 M tert-butanol also suggested formation of a partially folded state in the acid-denatured BLA. However, 5.5 M tert-butanol-induced state of BLA showed a non-cooperative thermal transition. All these results suggested formation of a partially folded state of the acid-denatured BLA in the presence of these alcohols. Furthermore, their effectiveness was found to be guided by their chain length, position of methyl groups and presence of the substituents.
Keywords
Acid-denatured state, Alcohol-induced states, Bacillus licheniformis α-amylase, Structural transition, Thermal denaturation
Divisions
InstituteofBiologicalSciences
Funders
University of Malaya Research Grant (RG160-11AFR),Postgraduate Research Fund (PV018/2011B)
Publication Title
Journal of Saudi Chemical Society
Volume
21
Issue
Spp.1
Publisher
Elsevier