title: Impact of intra-subunit domain-domain interactions on creatine kinase activity and stability.
abstract: Creatine kinase (CK) is a key enzyme in vertebrate excitable tissues. In this research, five conserved residues located on the intra-subunit domain-domain interface were mutated to explore their role in the activity and structural stability of CK. The mutations of Val72 and Gly73 decreased both the activity and stability of CK. The mutations of Cys74 and Val75, which had no significant effect on CK activity and structure, gradually decreased the stability and reactivation of CK. Our results suggested that the mutations might modify the correct positioning of the loop contributing to domain-domain interactions, and result in decreased stability against denaturation.
authors.affiliation: State Key Laboratory of Biomembrane and Membrane Biotechnology, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084, China.
authors.forename: Tong-Jin
authors.initials: TJ
authors.lastname: Zhao
authors.forename: Shan
authors.initials: S
authors.lastname: Feng
authors.forename: Yong-Liang
authors.initials: YL
authors.lastname: Wang
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Xue-Chun
authors.initials: XC
authors.lastname: Luo
authors.forename: Hai-Meng
authors.initials: HM
authors.lastname: Zhou
authors.forename: Yong-Bin
authors.initials: YB
authors.lastname: Yan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002942:Circular Dichroism; D052283:Creatine Kinase, MM Form / Q000737:chemistry* / Q000378:metabolism*; D004795:Enzyme Stability; D019791:Guanidine / Q000494:pharmacology; D007700:Kinetics; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D011485:Protein Binding; D011489:Protein Denaturation / Q000187:drug effects; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D021122:Protein Subunits / Q000378:metabolism*; D011817:Rabbits
chemical_list: D021122:Protein Subunits; D052283:Creatine Kinase, MM Form; D019791:Guanidine