The protective effects of osmolytes on arginine kinase unfolding and aggregation.
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.
Xia
Yong
Y
College of Life Science, Shandong Agricultural University, Shandong, Taian 271018, PR China.
Park
Yong-Doo
YD
Mu
Hang
H
Zhou
Hai-Meng
HM
Wang
Xiao-Yun
XY
Meng
Fan-Guo
FG
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*
D000817:Anilino Naphthalenesulfonates; D013395:Sucrose; D011392:Proline; D001122:Arginine Kinase; D019791:Guanidine; D005990:Glycerol; D004121:Dimethyl Sulfoxide