Participation of cysteine 30 residue in the folding process of ovalbumin evaluated in a refolding experiment using cysteine mutants
- Department of Biological Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi 753-8515 (Japan)
- Industrial Technology Center of Okayama Prefecture, Okayama 701-1296 (Japan)
To understand the role of cysteine (SH) residues in the folding of hen ovalbumin (OVA), SH-mutated OVAs, in which each SH residue was replaced by alanine (C11A, C30A, C367A, and C382A), were prepared. SDS-PAGE analysis under non-reducing conditions showed that the C11A and C30A mutants produced a disulfide (SS) isomer in addition to a protein with a native SS bond (Cys73–Cys120). The susceptibility to elastase digestion suggested that the Cys73 residue in the SS isomer participates as a counterpart of the SS bond. Upon refolding of the SH-mutated OVAs under the denatured and SS-reduced states, only C30A failed to refold into an intact form. This indicated that the Cys30 residue plays an important role in correct refolding. To confirm this, each of the four SH-mutated OVAs, in which the original SS-forming sites (C11/73/120A, C30/73/120A, C73/120/367A, and C73/120/382A) were deleted, was constructed and expressed. The C11/73/120A and C30/73/120A mutants formed no SS form, in contrast to C73/120A as a control. Thus, we concluded that Cys30 participates in the correct folding of OVA, and that its SS bond (Cys11–Cys30) is transiently generated during the early folding stage to avoid misfolding, and then the native SS form of OVA is regenerated through SH–SS exchanges.
- OSTI ID:
- 23127544
- Journal Information:
- Biochemical and Biophysical Research Communications, Vol. 495, Issue 1; Other Information: Copyright (c) 2017 Elsevier Inc. All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0006-291X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Renaturation of reduced hen egg white lysozyme containing two blocked sulfhydryl groups
Monitoring refolding of tailspike endorhamnosidase using capillary electrophoresis-laser induced tryptophan fluorescence