Biochemical characterization of a bifunctional acetaldehyde-alcohol dehydrogenase purified from a facultative anaerobic bacterium Citrobacter sp. S-77

详细信息    查看全文

• 作者：Kohsei Tsuji¹ ; ² ; Ki-Seok Yoon¹ ; ³ ; Seiji Ogo¹ ; ² ; ³ ; ^{ogotcm@mail.cstm.kyushu-u.ac.jp" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Coenzyme A-acylating ; Acetaldehyde-alcohol dehydrogenase ; Alcohol dehydrogenase ; Aldehyde dehydrogenase ; Kinetic parameters ; Specific activity ; Alcohol metabolism ; Citrobacter sp. S-77
• 刊名：Journal of Bioscience and Bioengineering
• 出版年：2016
• 出版时间：March 2016
• 年：2016
• 卷：121
• 期：3
• 页码：253-258
• 全文大小：515 K

文摘

Acetaldehyde-alcohol dehydrogenase (ADHE) is a bifunctional enzyme consisting of two domains of an N-terminal acetaldehyde dehydrogenase (ALDH) and a C-terminal alcohol dehydrogenase (ADH). The enzyme is known to be important in the cellular alcohol metabolism. However, the role of coenzyme A-acylating ADHE responsible for ethanol production from acetyl-CoA remains uncertain. Here, we present the purification and biochemical characterization of an ADHE from Citrobacter sp. S-77 (ADHE_S77). Interestingly, the ADHE_S77 was unable to be solubilized from membrane with detergents either 1% Triton X-100 or 1% Sulfobetaine 3-12. However, the enzyme was easily dissociated from membrane by high-salt buffers containing either 1.0 M NaCl or (NH₄)₂SO₄ without detergents. The molecular weight of a native protein was estimated as approximately 400 kDa, consisting of four identical subunits of 96.3 kDa. Based on the specific activity and kinetic analysis, the ADHE_S77 tended to have catalytic reaction towards acetaldehyde elimination rather than acetaldehyde formation. Our experimental observation suggests that the ADHE_S77 may play a pivotal role in modulating intracellular acetaldehyde concentration.