Structure and stability of recombinant bovine odorant-binding protein: II. Unfolding of the monomeric forms

PeerJ

article

Olga V. Stepanenko¹  Denis O. Roginskii¹  Olesya V. Stepanenko¹  Irina M. Kuznetsova¹  Vladimir N. Uversky¹  Konstantin K. Turoverov¹ 

[1] Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences;Department of Molecular Medicine and USF Health Byrd Alzheimer’s Research Institute, Morsani College of Medicine, University of South Florida;Peter the Great St. Petersburg Polytechnic University

关键词: Odorant-binding protein;    Ligand binding;    Disulfide bond;    Domain swapping;    Unfolding-refolding reaction;    Conformational stability;   

DOI  :  10.7717/peerj.1574

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

In a family of monomeric odorant-binding proteins (OBPs), bovine OBP (bOBP), that lacks conserved disulfide bond found in other OBPs, occupies unique niche because of its ability to form domain-swapped dimers. In this study, we analyzed conformational stabilities of the recombinant bOBP and its monomeric variants, the bOBP-Gly121+ mutant containing an additional glycine residue after the residue 121 of the bOBP, and the GCC-bOBP mutant obtained from the bOBP-Gly121+ form by introduction of the Trp64Cys/His155Cys double mutation to restore the canonical disulfide bond. We also analyzed the effect of the natural ligand binding on the conformational stabilities of these bOBP variants. Our data are consistent with the conclusion that the unfolding-refolding pathways of the recombinant bOBP and its mutant monomeric forms bOBP-Gly121+ and GCC-bOBP are similar and do not depend on the oligomeric status of the protein. This clearly shows that the information on the unfolding-refolding mechanism is encoded in the structure of the bOBP monomers. However, the process of the bOBP unfolding is significantly complicated by the formation of the domain-swapped dimer, and the rates of the unfolding-refolding reactions essentially depend on the conditions in which the protein is located.

【 授权许可】

CC BY