title: Effects of osmolytes on Pelodiscus sinensis creatine kinase: a study on thermal denaturation and aggregation.
abstract: The protective effect of osmolytes on the thermal denaturation and aggregation of Pelodiscus sinensis muscle creatine kinase (PSCK) was investigated by a combination of spectroscopic methods and thermodynamic analysis. Our results demonstrated that the addition of osmolytes, such as glycine and proline, could prevent thermal denaturation and aggregation of PSCK in a concentration-dependent manner. When the concentration of glycine and proline increased in the denatured system, the relative activation was significantly enhanced; meanwhile, the aggregation of PSCK during thermal denaturation was decreased. Spectrofluorometer results showed that glycine and proline significantly decreased the tertiary structural changes of PSCK and that thermal denaturation directly induced PSCK aggregation. In addition, we also built the 3D structure of PSCK and osmolytes by homology models. The results of computational docking simulations showed that the docking energy was relatively low and that the clustering groups were spread to the surface of PSCK, indicating that osmolytes directly protect the surface of the protein. P. sinensis are poikilothermic and quite sensitive to the change of ambient temperature; however, there were few studies on the thermal denaturation of reptile CK. Our study provides important insight into the protective effects of osmolytes on thermal denaturation and aggregation of PSCK.
authors.affiliation: College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo 315100, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Jinhyuk
authors.initials: J
authors.lastname: Lee
authors.forename: Qin-Xin
authors.initials: QX
authors.lastname: Jin
authors.forename: Nai-Yun
authors.initials: NY
authors.lastname: Fang
authors.forename: Yue-Xiu
authors.initials: YX
authors.lastname: Si
authors.forename: Shang-Jun
authors.initials: SJ
authors.lastname: Yin
authors.forename: Guo-Ying
authors.initials: GY
authors.lastname: Qian
authors.forename: Yong-Doo
authors.initials: YD
authors.lastname: Park
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D052283:Creatine Kinase, MM Form / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D004789:Enzyme Activation; D007700:Kinetics; D013058:Mass Spectrometry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D011489:Protein Denaturation; D016415:Sequence Alignment; D013816:Thermodynamics; D014426:Turtles / Q000145:classification / Q000235:genetics / Q000378:metabolism*
chemical_list: D052283:Creatine Kinase, MM Form
keywords: 1-anilinonaphthalene-8-sulfonate; ANS; ATP; Adenosine triphosphate; CK; Creatine kinase; DMSO; Dimethyl sulfoxide; LC–MS/MS; Osmolyte; PSCK; Pelodiscus sinensis; Pelodiscus sinensis creatine kinase; Thermal denaturation; creatine kinase; liquid chromatography-tandem mass spectrometry