Chinnawirotpisan Piyawan, Matsushita Kazunobu, Toyama Hirohide, Adachi Osao, Limtong Savitree, Theeragool Gunjana
Department of Microbiology, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.
Biosci Biotechnol Biochem. 2003 May;67(5):958-65. doi: 10.1271/bbb.67.958.
High NAD-dependent alcohol dehydrogenase (ADH) activity was found in the cytoplasm when a membrane-bound, quinoprotein, ADH-deficient mutant strain of Acetobacter pasteurianus SKU1108 was grown on ethanol. Two NAD-dependent ADHs were separated and purified from the supernatant fraction of the cells. One (ADH I) is a trimer, consisting of an identical subunit of 42 kDa, while the other (ADH II) is a homodimer, having a subunit of 31 kDa. One of the two ADHs, ADH II, easily lost the activity during the column chromatographies, which could be stabilized by the addition of DTT and MgCl2 in the column buffer. ADH I but not ADH II contained approximately one zinc atom per subunit. The N-terminal amino acid analysis indicated that ADH I and ADH II have homology to the long-chain and short-chain ADH families, respectively. ADH I showed a preference for primary alcohols, while ADH II had a preference for secondary alcohols. The two ADHs showed clear difference in their kinetics on ethanol, acetaldehyde, NAD, and NADH. The physiological function of both ADH I and ADH II are also discussed.
当巴氏醋杆菌SKU1108的膜结合醌蛋白乙醇脱氢酶（ADH）缺陷型突变株在乙醇上生长时，在细胞质中发现了高NAD依赖性乙醇脱氢酶（ADH）活性。从细胞的上清液部分分离并纯化了两种NAD依赖性ADH。一种（ADH I）是三聚体，由42 kDa的相同亚基组成，而另一种（ADH II）是同型二聚体，具有31 kDa的亚基。两种ADH之一，ADH II，在柱色谱过程中很容易失去活性，在柱缓冲液中添加DTT和MgCl2可以使其稳定。ADH I每个亚基含有约一个锌原子，而ADH II则不含。N端氨基酸分析表明，ADH I和ADH II分别与长链和短链ADH家族具有同源性。ADH I对伯醇有偏好，而ADH II对仲醇有偏好。两种ADH在乙醇、乙醛、NAD和NADH的动力学上表现出明显差异。还讨论了ADH I和ADH II的生理功能。
