title: The protective effects of osmolytes on arginine kinase unfolding and aggregation.
abstract: Osmolytes are a series of different kinds of small molecules that can maintain the correct conformation of protein by acting as molecular chaperons. In this study, the protective effects of four compatible osmolytes, i.e., proline, sucrose, DMSO and glycerol, were studied during arginine kinase (EC 2.7.3.3) unfolding and aggregation. The results showed that all the osmolytes applied in this study obviously prevented AK unfolding and inactivation that was due to a GdnHCl denaturant by reducing the inactivation rate constants (k(i)), increasing the transition free energy changes (DeltaDeltaG(i)) and increasing the value for the midpoint of denaturation (C(m)). Furthermore, the osmolytes remarkably prevented AK aggregation in a concentration-dependent manner during AK refolding. Our results strongly indicated that osmolytes were not only metabolism substrates, but they were also important compounds with significant physiological protective functions for proteins, especially in some extremely harsh environments.
authors.affiliation: College of Life Science, Shandong Agricultural University, Shandong, Taian 271018, PR China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Xia
authors.forename: Yong-Doo
authors.initials: YD
authors.lastname: Park
authors.forename: Hang
authors.initials: H
authors.lastname: Mu
authors.forename: Hai-Meng
authors.initials: HM
authors.lastname: Zhou
authors.forename: Xiao-Yun
authors.initials: XY
authors.lastname: Wang
authors.forename: Fan-Guo
authors.initials: FG
authors.lastname: Meng
mesh_terms: D000817:Anilino Naphthalenesulfonates; D000818:Animals; D001122:Arginine Kinase / Q000737:chemistry* / Q000378:metabolism*; D004121:Dimethyl Sulfoxide / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D005453:Fluorescence; D005990:Glycerol / Q000494:pharmacology*; D006110:Grasshoppers / Q000201:enzymology; D019791:Guanidine / Q000494:pharmacology; D007700:Kinetics; D011392:Proline / Q000494:pharmacology*; D011489:Protein Denaturation / Q000187:drug effects; D017510:Protein Folding; D020836:Protein Structure, Quaternary / Q000187:drug effects; D013050:Spectrometry, Fluorescence; D013395:Sucrose / Q000494:pharmacology*
chemical_list: D000817:Anilino Naphthalenesulfonates; D013395:Sucrose; D011392:Proline; D001122:Arginine Kinase; D019791:Guanidine; D005990:Glycerol; D004121:Dimethyl Sulfoxide