鉴定参与 Geobacillus thermodenitrificans NG80-2 烷烃降解的广谱醛脱氢酶。
Characterization of a broad-range aldehyde dehydrogenase involved in alkane degradation in Geobacillus thermodenitrificans NG80-2.
机构信息
TEDA School of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjin 300457, PR China.
出版信息
Microbiol Res. 2010 Oct 20;165(8):706-12. doi: 10.1016/j.micres.2010.01.006. Epub 2010 Feb 18.
An aldehyde dehydrogenase (ALDH) involved in alkane degradation in crude oil-degrading Geobacillus thermodenitrificans NG80-2 was characterized in vitro. The ALDH was expressed heterologously in Escherichia coli and purified as a His-tagged homotetrameric protein with a subunit of 57 kDa based on SDS-PAGE and Native-PAGE analysis. The purified ALDH-oxidized alkyl aldehydes ranging from formaldehyde (C₁) to eicosanoic aldehyde (C₂₀) with the highest activity on C₁. It also oxidized several aromatic aldehydes including benzaldehyde, phenylacetaldehyde, o-chloro-benzaldehyde and o-phthalaldehyde. The ALDH uses only NAD(+) as the cofactor, and has no reductive activity on acetate or hexadecanoic acid. Therefore, it is an irreversible NAD(+)-dependent aldehyde dehydrogenase. Kinetic parameters, temperature and pH optimum of the enzyme, and effects of metal ions, EDTA and Triton X-100 on the enzyme activity were investigated. Physiological roles of the ALDH for the survival of NG80-2 in oil reservoirs are discussed.
在原油降解嗜热脱硫杆菌 NG80-2 中发现了一种参与烷烃降解的醛脱氢酶（ALDH），并在体外对其进行了表征。该 ALDH 在大肠杆菌中异源表达，并根据 SDS-PAGE 和 Native-PAGE 分析，纯化得到带有 His 标签的四聚体同源蛋白，亚基分子量为 57 kDa。纯化的 ALDH 可氧化从甲醛（C₁）到二十烷醛（C₂₀）的各种直链烷基醛，其中对 C₁ 的活性最高。它还可氧化多种芳香醛，包括苯甲醛、苯乙醛、邻氯苯甲醛和邻苯二甲醛。ALDH 仅使用 NAD(+)作为辅助因子，对乙酸盐或十六烷酸没有还原活性。因此，它是一种不可逆的 NAD(+)-依赖型醛脱氢酶。研究了该酶的动力学参数、温度和 pH 最适值，以及金属离子、EDTA 和 Triton X-100 对酶活性的影响。讨论了 ALDH 对 NG80-2 在油藏中生存的生理作用。
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