Impact of intra-subunit domain-domain interactions on creatine kinase activity and stability.
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.
Zhao
Tong-Jin
TJ
State Key Laboratory of Biomembrane and Membrane Biotechnology, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084, China.
Feng
Shan
S
Wang
Yong-Liang
YL
Liu
Yang
Y
Luo
Xue-Chun
XC
Zhou
Hai-Meng
HM
Yan
Yong-Bin
YB
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
D021122:Protein Subunits; D052283:Creatine Kinase, MM Form; D019791:Guanidine