Covalently anchoring of a ligand/metal via polar amino acid side chain(s) is often observed in metalloenzyme, while the substitutability of metal-binding sites remains elusive. In this study, we utilized a zinc-dependent alcohol dehydrogenase from Thermoanaerobacter brockii (TbSADH) as a model enzyme, analyzed the sequence conservation of the three residues Cys37, His59, and Asp150 that bind the zinc ion, and constructed the mutant library. After experimental validation, three out of 224 clones, which showed comparative conversion and ee values as the wild-type enzyme in the asymmetric reduction of the model substrate tetrahydrofuran-3-one, were screened out. The results reveal that the metal-binding sites in TbSADH are substitutable without tradeoff in activity and stereoselectivity, which lay a foundation for designing ADH-catalyzed new reactions via metal ion replacement.
Alcohol Dehydrogenase/metabolism* ; Catalytic Domain ; Ligands ; Protein Domains ; Zinc/metabolism*

BACKGROUND: Elevated blood pressure is a major preventable cause of cardiovascular diseases. Alcohol consumption is a well-known risk factor of elevated blood pressure. The aldehyde dehydrogenase 2 (ALDH2) polymorphism is common in Eastern Asians, and inactive ALDH2 genotypes are associated with both avoiding alcohol consumption and aldehyde accumulation. Therefore, this study assessed the associations between alcohol consumption and hypertension and blood pressure according to the ALDH2 genotypes.METHODS: This study consists of 8,526 participants in the Dong-gu Study. Multivariate logistic regression was used to calculate the odds ratio (OR) according to alcohol consumption after stratifying by gender and ALDH2 genotypes. Multivariate linear regression was performed to estimate the systolic blood pressure (SBP) and diastolic blood pressure (DBP) according to the amount of alcohol consumed.RESULTS: In men, alcohol consumption was positively associated with both SBP and DBP in active ALDH2 carriers, but not in inactive ALDH2 carriers. In active ALDH2 carriers, compared to non-drinkers, the OR of hypertension was 1.16 (95% confidence interval [CI], 0.91–1.49) for < 1 drink/day, and 1.44 (95% CI, 1.15–1.80) for ≥ 1 drink/day in men. With each 1 drink/day increase, SBP and DBP increased by 3 and 1 mmHg in men, respectively. There was no significant association between ALDH2 genotypes and hypertension and blood pressure in women.CONCLUSION: ALDH2 genotype modified the association between alcohol consumption and blood pressure in men. There was a positive relationship between alcohol consumption and blood pressure in active ALDH2 carriers, but no significant relationship in inactive ALDH2 carriers.
Acetaldehyde ; Alcohol Drinking ; Aldehyde Dehydrogenase ; Asian Continental Ancestry Group ; Blood Pressure ; Cardiovascular Diseases ; Cohort Studies ; Female ; Genotype ; Humans ; Hypertension ; Linear Models ; Logistic Models ; Male ; Odds Ratio ; Oxidoreductases ; Risk Factors

Objective To explore the change rules of blood ethanol and blood acetaldehyde concentration, the impairment of psychomotor functions of different acetaldehyde dehydrogenase （ALDH） 2 genotype individuals after alcohol consumption and the relationship among them. Methods The ALDH2 genotypes in seventy-nine healthy volunteers were obtained by SNaPshot^TM method, then divided into ALDH2*1/*1 （wild type） and ALDH2*1/*2 （mutant type） group. After volunteers consumed 1.0 g/kg of alcohol, blood ethanol concentration and blood acetaldehyde concentration at a series of time points before and after alcohol consumption and psychomotor functions, such as, visual selective response time, auditory simple response time and tracking experiment were detected. Biphasic alcohol response questionnaires were collected. Results After alcohol consumption, ALDH2*1/*2 group's blood ethanol and blood acetaldehyde concentration reached the peak earlier than ALDH2*1/*1 group. Its blood acetaldehyde concentration was higher than that of ALDH2*1/*1 group, 1-6 h after alcohol consumption. The psychomotor functions, such as visual selective response time and auditory simple response time in ALDH2*1/*2 group were more significantly impaired than those in ALDH2*1/*1 group after alcohol consumption. There was no statistical significance between the two groups in excitement or sedation reactions （P>0.05）. Pearson correlation coefficient test showed that blood acetaldehyde concentration was related with psychomotor function. Conclusion There are significant differences between the psychomotor function of ALDH2 wild type and mutant type individuals after alcohol consumption estimated to be related to the difference in blood acetaldehyde concentration after alcohol consumption.
Acetaldehyde/metabolism* ; Alcohol Drinking/blood* ; Aldehyde Dehydrogenase/genetics* ; Aldehyde Dehydrogenase, Mitochondrial ; Aldehyde Oxidoreductases ; Ethanol/metabolism* ; Genotype ; Humans ; Polymorphism, Genetic/genetics* ; Psychomotor Performance/physiology*

Alcohol consumption is a serious health issue in Korea in terms of the amount consumed and the behavior related to its consumption. Aldehyde dehydrogenase 2 (ALDH2) is a key enzyme in alcohol metabolism that degrades acetaldehyde to nontoxic acetic acid. The enzyme is coded by the ALDH2 gene, which is commonly polymorphic in East Asian populations. A point mutation in the ALDH2 gene (the rs671 allele) yields an inactive form of ALDH2 that causes acetaldehyde accumulation in the body after alcohol consumption, thereby inhibiting normal alcohol metabolism. Individuals who are homozygous for polymorphism in ALDH2 tend to refrain from drinking alcohol, decreasing their chances of developing alcoholism and exposure to the associated risks. Mendelian randomization (MR) studies have demonstrated that alcohol consumption predicted by ALDH2 genotype is causally related to cardiovascular risks. Moreover, recent MR studies suggest that the ALDH2 variant has mechanistic effects on some disease outcomes or mortality through increased blood levels of acetaldehyde, showing differences therein between heterozygotes (ALDH2*2*2) and homozygotes (ALDH2*1*2) in those who consume alcohol. Accordingly, consideration of ALDH2 genotype in alcohol prevention programs is warranted. In conclusion, strategies that incorporate genetic information and provide an evidential basis from which to help people make informed decisions on alcohol consumption are urgently required.
Acetaldehyde ; Acetic Acid ; Alcohol Drinking* ; Alcoholism ; Aldehyde Dehydrogenase* ; Asian Continental Ancestry Group ; Drinking ; Genotype ; Heterozygote ; Homozygote ; Humans ; Korea* ; Mendelian Randomization Analysis ; Metabolism ; Mortality ; Point Mutation ; Random Allocation

BACKGROUND/OBJECTIVES: Telomere length is a useful biomarker for determining general aging status. Some studies have reported an association between alcohol consumption and telomere length in a general population; however, it is unclear whether the alcohol flush reaction, which is an alcohol-related trait predominantly due to acetaldehyde dehydrogenase deficiency, is associated with telomere length. This cross-sectional study aimed to evaluate the associations of alcohol consumption and alcohol flush reaction with leukocyte telomere length (LTL). SUBJECTS/METHODS: The study included 1,803 Korean adults. Participants provided blood specimens for LTL measurement assay and reported their alcohol drinking status and the presence of an alcohol flush reaction via a questionnaire-based interview. Relative LTL was determined by using a quantitative polymerase chain reaction. Statistical analysis used multiple linear regression models stratified by sex and age groups, and potential confounding factors were considered. RESULTS: Age-specific analyses showed that heavy alcohol consumption (> 30 g/day) was strongly associated with a reduced LTL in participants aged ≥ 65 years (P < 0.001) but not in younger participants. Similarly, the alcohol flush reaction was associated with a reduced LTL only in older participants who consumed > 15 g/day of alcohol (P < 0.01). No significant alcohol consumption or alcohol flush reaction associations with LTL were observed in the sex-specific analyses. CONCLUSIONS: The results suggest that older alcohol drinkers, particularly those with the alcohol flush reaction, may have an accelerated aging process.
Acetaldehyde ; Adult* ; Aging ; Alcohol Drinking* ; Aldehyde Dehydrogenase ; Cross-Sectional Studies ; Humans ; Leukocytes* ; Linear Models ; Oxidoreductases ; Polymerase Chain Reaction ; Telomere*

Ethylene glycol is a widely used and readily available substance. Ethylene glycol ingestion does not cause direct toxicity; however, its metabolites are highly toxic and can be fatal even in trace amounts. Poisoning is best diagnosed through inquiry, but as an impaired state of consciousness is observed in most cases, poisoning must be suspected when a significantly elevated osmolar gap or high anion gap metabolic acidosis is found in blood tests. Hemodialysis and alcohol dehydrogenase inhibitors such as ethanol and fomepizole are a part of the basic treatment, and timely diagnosis and treatment are crucial because any delays can lead to death. However, there are few reported cases in Korea, and no report on the use of fomepizole. Herein, we report a case of acute renal failure caused by ethylene glycol poisoning that was treated with fomepizole and hemodialysis and present a literature review.
Acid-Base Equilibrium ; Acidosis ; Acute Kidney Injury* ; Alcohol Dehydrogenase ; Consciousness ; Diagnosis ; Eating ; Ethanol ; Ethylene Glycol* ; Hematologic Tests ; Korea ; Poisoning ; Renal Dialysis ; Renal Replacement Therapy*

BACKGROUND: Facial flushing response to drinking is observed in East Asians with deficient activity of the variant aldehyde dehydrogenase 2 genotype. This study examined the role of flushing response in the relationship between alcohol consumption and dyslipidemia. METHODS: This cross-sectional study included 1,443 Korean men, including 261 non-drinkers, 470 flushers and 712 non-flushers. Based on a questionnaire, weekly alcohol consumption was assessed and categorized into 4 groups. Dyslipidemia was defined by the National Cholesterol Education Program-Adult Treatment Panel III criteria. After adjusting for confounding factors, we evaluated the relationship between weekly alcoholic drinks and dyslipidemia in flushers and non-flushers by comparing with non-drinkers, using a multi-variable logistic regression analysis. RESULTS: Non-flushers had a significant relationship between hypertriglyceridemia and alcohol consumption in two groups (4-8 drinks: adjusted odds ratio [aOR] 1.937, 95% confidence interval [CI] 1.029-3.644; ≥16 drinks: aOR 2.118, 95% CI 1.272-3.527) in contrast to flushers, who showed no significant relationship between hypertriglyceridemia and alcohol consumption. Non-flushers had a significant relationship to low serum high density lipoprotein (HDL) cholesterol levels in four groups (<4 drinks: aOR 0.428, 95% CI 0.277-0.662; 4-8 drinks: aOR 0.409, 95% CI 0.216-0.774; 8-16 drinks: aOR 0.285, 95% CI 0.152-0.536; ≥16 drinks: aOR 0.343, 95% CI 0.207-0.568), and flushers had a significant relationship in two groups (8-16 drinks: aOR 0.234, 95% CI 0.102-0.536; ≥16 drinks: aOR 0.342, 95% CI 0.166-0.705). CONCLUSIONS: Our results suggest that drinking alcohol increases the risk of hypertriglyceridemia in non-flushers and the risk of low HDL cholesterol flushers.
Alcohol Drinking* ; Alcoholics ; Aldehyde Dehydrogenase ; Asian Continental Ancestry Group ; Cholesterol ; Cholesterol, HDL ; Cross-Sectional Studies ; Drinking ; Dyslipidemias* ; Education ; Flushing* ; Genotype ; Humans ; Hypertriglyceridemia ; Lipoproteins ; Logistic Models ; Male* ; Odds Ratio ; Triglycerides

Aldehyde dehydrogenase 2 (ALDH2), as one of the most important alcohol metabolizing enzymes, plays a significant role in the detoxification process of acetaldehyde which is a main carcinogenic product of alcoholic metabolism. Alteration in its genotypes (particularly at the site of rs671) is closely associated with a variety of tumors in drinkers. Recent advance in the research of the association of the ALDH2 gene rs671 polymorphisms with cancer susceptibility in drinkers is reviewed.
Alcohol Drinking ; genetics ; Aldehyde Dehydrogenase ; genetics ; Aldehyde Dehydrogenase, Mitochondrial ; Genetic Predisposition to Disease ; Humans ; Neoplasms ; etiology ; genetics ; Polymorphism, Genetic

The protective effect of EtOAc fraction of Limonium tetragonum extract (EALT) against alcoholinduced hepatotoxicity was assessed following acute ethanol intoxication in Spraque-Dawley rats. EALT (200 mg/kg p.o.) was administrated once before alcohol intake (8 g/kg, p.o.). Blood ethanol concentration, and the activities of alcohol metabolic enzymes, alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) in the liver were measured. Also, the formation of malondialdehyde (MDA) and the activities of antioxidant enzymes, superoxide dismutase (SOD), glutathione peroxidase (GSH-px), catalase were determined after acute alcohol exposure. Pretreatment of rats received ethanol with EALT significantly decreased blood ethanol concentration and elevated the activities of ADH and ALDH in liver. The increased MDA level was decreased, and the reduced activities of SOD, GSH-px and catalase were markedly preserved by the treatment with EALT. This study suggests that EALT prevent hepatic injury induced by acute alcohol which is likely related to its modulation on the alcohol metabolism and antioxidant enzymes activities.
Alcohol Dehydrogenase ; Aldehyde Dehydrogenase ; Animals ; Catalase ; Ethanol* ; Glutathione Peroxidase ; Liver* ; Malondialdehyde ; Metabolism* ; Plumbaginaceae* ; Rats ; Salt-Tolerant Plants ; Superoxide Dismutase

BACKGROUND/OBJECTIVES: It is well-known that alcohol consumption is associated with stroke risk as well as with aldehyde dehydrogenase 2 gene (ALDH2) polymorphisms. However, it is unclear whether ALDH2 polymorphisms are associated with stroke risk independent of alcohol consumption and whether such association is modified by sex. We evaluated sex-specific associations of a common ALDH2 polymorphism and alcohol consumption with stroke risk in a Korean population. SUBJECTS/METHODS: We conducted a prospective cohort study involving 8,465 men and women, aged 40-69 years and free of stroke between June, 2001 and January, 2003, and followed for the development of stroke. We identified new cases of stroke, which were self-reported or ascertained from vital registration data. Based on genome-wide association data, we selected a single-nucleotide polymorphism (rs2074356), which shows high linkage disequilibrium with the functional polymorphism of ALDH2. We conducted Cox proportional hazards regression analysis considering potential risk factors collected from a baseline questionnaire. RESULTS: Over the median follow-up of 8 years, 121 cases of stroke were identified. Carrying the wild-type allele of the ALDH2 polymorphism increased stroke risk among men. The multivariate hazard ratio [95% confidence interval] of stroke was 2.02 [1.03-3.99] for the wild-type allele compared with the mutant alleles, but the association was attenuated after controlling for alcohol consumption. Combinations of the wild-type allele and other risk factors of stroke, such as old age, diabetes mellitus, and habitual snoring, synergistically increased the risk among men. Among women, however, the ALDH2 polymorphism was not associated with stroke risk. CONCLUSIONS: The prospective cohort study showed a significant association between a common ALDH2 polymorphism and stroke risk in Korean men, but not in Korean women, and also demonstrated that men with genetic disadvantages gain more risk when having risk factors of stroke. Thus, these men may need to make more concerted efforts to control modifiable risk factors of stroke.
Alcohol Drinking* ; Aldehyde Dehydrogenase* ; Alleles ; Cohort Studies* ; Diabetes Mellitus ; Female ; Follow-Up Studies ; Humans ; Linkage Disequilibrium ; Male ; Prospective Studies* ; Surveys and Questionnaires ; Risk Factors ; Snoring ; Stroke*