Single amino-acid substitution in the N-terminal arm altered the tetramer stability of rat muscle lactate dehydrogenase A
文献类型：期刊论文
| 作者 | Yuan, C; Hu, HY; Xu, GJ |
| 刊名 | SCIENCE IN CHINA SERIES C-LIFE SCIENCES
 |
| 出版日期 | 2001 |
| 卷号 | 44期号:6页码:576-584 |
| 关键词 | lactate dehydrogenase A N-terminal residues size-exclusion chromatograph tetramer stability site-directed mutagenesis unfolding experiments subunit interaction |
| 通讯作者 | Xu, GJ (reprint author), Chinese Acad Sci, Shanghai Inst Biol Sci, Inst Biochem & Cell Biol, Shanghai 200031, Peoples R China., |
| 英文摘要 | Lactate dehydrogenase A (LDHA) is a well-characterized tetrameric enzyme. Its N-terminal arm, comprised of an alpha-helix and a beta-strand, was suggested to be essential for subunit interactions. To examine the critical amino acid residues in the N-terminus involved in the subunit association, two single-point mutants, Leu3Pro (L3P) and IIe8Glu ([BE), have been constructed. We compared the stability of WT-LDHA (WT) and its variants by unfolding experiments. For WT, a dimeric but inactive intermediate was observed by size-exclusion chromatography at 0.6-0.8 mol/L GdmCl. Leu3Pro exists in an active tetrameric structure in aqueous solution as WT does, but it dissociates into dimers under lower concentration of GdmCl (0.2 mol/L). In aqueous solution, the IIe8Glu variant exists predominantly in the dimeric form with increased K-m and decreased k(cat) as compared with those of WT and L3P. However, the activity of IIe8Glu increases significantly in the presence of sodium sulfate. In conclusion, two mutants are less stable than WT in oligomer structure. Results also support the fact that some residues in the N-terminal arm, especially the Leu8 in the beta-structure, contribute the important binding energies to the dimerization of dimers, which might affect the assembly of the enzyme as well as the catalytic function. |
| 学科主题 | Life Sciences & Biomedicine - Other Topics |
| 类目[WOS] | Biology |
| 关键词[WOS] | LACTIC-DEHYDROGENASE ; RECONSTITUTION ; ASSOCIATION ; DENATURATION ; PROTEINS ; PATHWAY ; ENZYME |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000175029600003 |
| 版本 | 出版稿 |
| 源URL | [http://202.127.25.143/handle/331003/2678]  |
| 专题 | 上海生化细胞研究所_上海生科院生化细胞研究所 |
| 推荐引用方式 GB/T 7714 | Yuan, C,Hu, HY,Xu, GJ. Single amino-acid substitution in the N-terminal arm altered the tetramer stability of rat muscle lactate dehydrogenase A[J]. SCIENCE IN CHINA SERIES C-LIFE SCIENCES,2001,44(6):576-584. |
| APA | Yuan, C,Hu, HY,&Xu, GJ.(2001).Single amino-acid substitution in the N-terminal arm altered the tetramer stability of rat muscle lactate dehydrogenase A.SCIENCE IN CHINA SERIES C-LIFE SCIENCES,44(6),576-584. |
| MLA | Yuan, C,et al."Single amino-acid substitution in the N-terminal arm altered the tetramer stability of rat muscle lactate dehydrogenase A".SCIENCE IN CHINA SERIES C-LIFE SCIENCES 44.6(2001):576-584. |
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