The D14 and R138 ion pair is involved in dimeric arginine kinase activity, structural stability and folding
The D14 and R138 ion pair is involved in dimeric arginine kinase activity, structural stability and folding
复制标题
D14 和 R138 离子对参与二聚精氨酸激酶活性、结构稳定性和折叠
DOI：
10.1016/j.ijbiomac.2014.02.039
复制
发表时间：
2014-05-01
影响因子：
8.2
通讯作者：
Xu, Kai-Lin
中科院分区：
文献类型：
--
作者：
Geng, Hong-Li;Bian, Mei-Ru;Xu, Kai-Lin
精氨酸激酶（AK）是无脊椎动物细胞能量代谢的关键酶。二聚体AK中有两个保守的氨基酸残基D14和R138，它们形成亚基间的氢键。在刺参中，这些残基的突变引起明显的活性丧失，构象变化和明显的底物协同作用改变。突变（R138 G、R138 A和D14 G）消除了D14和R138的相互作用，破坏了S的结构或构象。我的天这些R138 G、R138 A和D14 G突变改变了二聚体AK的天然组装，并使其处于部分未折叠状态。这些突变AK的部分未折叠状态使它们在环境胁迫下易于聚集。D14 E/R138 K和R138 K突变体AK与野生型AK具有相似的互作特性，可替代D14和R138的互作。这些结果表明，D14和R138的相互作用参与了AK的活性、底物协同作用和结构稳定性。(C)2014爱思唯尔有限公司版权所有。
Arginine kinase (AK) is a key enzyme in cellular energy metabolism of invertebrates. There are two conserved amino acid residues D14 and R138 in dimeric AK which form inter-subunit hydrogen bond. In Stichopus japonicus AK, mutations in these residues caused pronounced loss of activity, conformational changes and distinct substrate synergism alteration. Mutations (R138G, R138A and D14G) abolished D14 and R138 interaction disrupted the structure or conformation of S. japonicus AK. These R138G, R138A and D14G mutations changed their native assembles of dimeric AK and caused them in a partially unfolded state. The partially unfolded state of these mutant AKs made them prone to aggregate under environmental stress. The D14E/R138K and R138K mutant AKs showed similar characteristics to those of WT AK for forming the interaction which could replacement roles of D14 and R138 interaction. These results suggested that D14 and R138 interaction is involved in AK's activity, substrate synergism and structural stability. (C) 2014 Elsevier B.V. All rights reserved.