A change of the metal-specific active site structure of superoxide dismutase from Porphyromonas gingivalis by the mutation of Gly155Thr.

Gly155Thr 突变导致牙龈卟啉单胞菌超氧化物歧化酶金属特异性活性位点结构的变化。

• 批准号: 16591874
• 负责人: HIRAOKA B.Yukihiro
• 金额: $ 2.11万
• 依托单位: Matsumoto Dental University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16591874/
• 关键词: Reactive oxygen; SOD; cambialistic enzyme; Metallo enzyme; Oxidoreductase; Porphyromanas gingivalis; site-directed mutagenesis; EPR spectrum

Mn-superoxide dismutases (SODs), Fe-SODs and cambialistic SODs, its include P.gingivalis (P.g.) SOD, have a large degree of sequence homology and X-ray structural similarity. Gly155 of P.g.-SOD is located about 11Å from active metal sites and is mostly conserved in aligned amino acid sequences of Mn-SODs, but is substituted for Thr in most Fe-SODs. In order to clarify the structural bases of the metal-specific activity, we analyzed using high-field electron paramagnetic resonance spectroscopy.We found that Gly155Thr mutation changes the metal-specific activity drastically from a cambialistic type to close to Fe-specific type. Also the Gly155Thr mutant of P.g.-SOD changed the Mn(II) spectrum so that it closely resembled the spectrum of Mn-substituted Fe SOD from E.coli. It has been concluded that Gly155 had universality as one of the amino acid residue which determines the Mn specific activity and Thr on same position had universality as one of the amino acid residue which determines the Fe specifc activity on SODs.

锰超氧化物歧化酶（SODs）、铁超氧化物歧化酶（Fe-SODs）和形相型SODs，其主要包括牙龈型超氧化物歧化酶(P.g。SOD，具有很大程度的序列同源性和x射线结构相似性。P.g.-SOD的Gly155位于活性金属位点11Å左右，在mn - sod的排列氨基酸序列中大多保守，但在大多数fe - sod中被Thr取代。为了弄清金属比活度的结构基础，我们利用高场电子顺磁共振谱分析了金属比活度。我们发现Gly155Thr突变使金属特异性活性从形生型急剧改变为接近铁特异性活性。此外，p.g.s osod的Gly155Thr突变体改变了Mn（II）光谱，使其与大肠杆菌中Mn取代Fe SOD的光谱非常相似。结果表明，Gly155作为决定锰比活性的氨基酸残基具有通用性，同一位置上的Thr作为决定sod上铁比活性的氨基酸残基具有通用性。

项目成果

Manganese(II) zero-field interaction in cambialistic and manganese superoxide dismutase and its relationship to the structure of the metal binding site.

锰（II）在camambialistic和锰超氧化物歧化酶中的零场相互作用及其与金属结合位点结构的关系。

• 发表时间: 2004
• 期刊: J Amer Chem Soc 126(9)
• 作者: Sun Un;et al.
• 通讯作者: et al.

Effects of Substrate Analogues and pH on Manganese Superoxide Dismutases

底物类似物和 pH 对锰超氧化物歧化酶的影响

• 发表时间: 2006
• 期刊: Biochemistry 45・6
• 作者: Tabares;LC. et al.
• 通讯作者: LC. et al.

Manganese (II) zero-field interaction in cambialistic and manganese superoxide dismutase and its relationship to the structure of the metal binding site.

锰（II）在camambialistic和锰超氧化物歧化酶中的零场相互作用及其与金属结合位点结构的关系。

• 发表时间: 2004
• 期刊: J. Amer. Chem. Soc. 126・9
• 作者: Sun Un;et al.
• 通讯作者: et al.