Zhao Tong-Jin, Feng Shan, Wang Yong-Liang, Liu Yang, Luo Xue-Chun, Zhou Hai-Meng, Yan Yong-Bin
State Key Laboratory of Biomembrane and Membrane Biotechnology, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084, China.
FEBS Lett. 2006 Jul 10;580(16):3835-40. doi: 10.1016/j.febslet.2006.05.076. Epub 2006 Jun 15.
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.
肌酸激酶（CK）是脊椎动物可兴奋组织中的一种关键酶。在本研究中，对位于亚基内结构域-结构域界面的五个保守残基进行了突变，以探究它们在CK活性和结构稳定性中的作用。Val72和Gly73的突变降低了CK的活性和稳定性。对CK活性和结构无显著影响的Cys74和Val75的突变，逐渐降低了CK的稳定性和再激活能力。我们的结果表明，这些突变可能会改变有助于结构域-结构域相互作用的环的正确定位，并导致抗变性稳定性降低。
