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Human alcohol dehydrogenase ( alcohol dehydrogenase , ADH ) and aldehyde dehydrogenase (aldehyde dehydrogenase, ALDH) in the process of ethanol metabolism plays an important role. ADH and ALDH in the human body are fully equipped , can be quickly obtained decomposition ethanol, to reduce what the impact on the central nervous , and thus even if the intake of a certain amount of ethanol, they contain ethanol can also be obtained in a very short period sufficiently metabolism. In the human body , ADH in general can fully express , and the expression level was essentially flat . Lack ALDH individuals within the crowd more ALDH lack of will lead to ethanol can not be completely decomposed into water and carbon dioxide , but continue to exist in the form of acetaldehyde in the body , nausea Yu Tu people drunk , unconscious discomfort and other central nervous paralysis , drunkenness symptoms . Which ALDH-2 is known to have a high degree of genetic polymorphism and gene closely related to the drinking behavior of the Asian population . In recent years, as people get a new , more effective hangover hepatoprotective drugs increasingly urgent demand , the research work on ALDH more far-reaching significance. Using PCR technology , the cloned human aldh2 gene , build plasmid pUCm-aldh2 was their sequencing , fully consistent with the expected sequence . Plasmid pUCm-aldh2 template PCR, and this reorganization of the restriction sites aldh2 gene to the prokaryotic expression vector pET22b () IPTG induction confirm people ALDH - 2 has achieved a high level of protein expression , the best expression of the conditions of 37 ° C , 1mmol / L IPTG concentration , induced expression 6h, the total expression of about 30% of the protein . Secondary washing inclusion bodies , can be obtained with high purity of the target protein , which provided for the industrial production conditions . Recombinant human ALDH-2 fusion 6 × His tag use Ni 2 affinity purified , ultra-high purity target protein affinity chromatography results show that , when the imidazole concentration reached 40mmol / L or so , and begin with the target protein washed out until the the imidazole concentration reaches end 100mmol / L . Target protein purified by the containing arginine the denaturing solution after refolding activity assay showed that the refolding protein ALDH activity , the specific activity of about 331.7U/mg .
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