H. Werner Goedde

Electrophoretic and biochemical studies of human aldehyde dehydrogenase isozymes in various tissues

Abstract Four major ALDH isozymes have been identified in human tissues using starch gel electrophoresis and isoelectric focusing. The isozyme bands have been termed as ALDH I, II, III and IV according to their decreasing electrophoretic migration and increasing isoelectric point. The isozymes have been partially purified via preparative isoelectric focusing. Kinetic characteristics of ALDH I and II were found to be quite similar to ALDH enzyme 2 and enzyme 1 described earlier by Greenfield and Pietruszko (Biochem Biophys Acta, 483 35–45 1977). ALDH III and IV showed a very high Km for propionaldehyde (1.0–1.5 mM at pH 9.5) and were not inhibited by disulfiram at pH 9.5. A variant phenotype of ALDH which lacked in isozyme I was detected in various tissues from Japanese individuals. Comparative kinetic properties of normal and variant enzyme are given.

Aldehyde dehydrogenase isozyme variation and alcoholism in Japan.

Aldehyde dehydrogenase (ALDH) isozyme composition in hair roots was determined using isoelectric focusing in 105 healthy individuals, 175 alcoholics, 86 schizophrenics and 47 drug dependents. The incidence of ALDH isozyme I deficiency in healthy populations in Japan was found to be about 40%. Among alcoholics, however, only 2.3% individuals had the isozyme deficiency. There was no difference between normal controls, schizophrenics and drug dependents regarding the incidence of ALDH isozyme I deficiency. These observations indicate a possible protective role of ALDH isozymes against alcoholism. The higher frequency of ALDH isozyme I deficiency in Japanese may explain why alcoholism in Japan has been less frequent than in European and North American countries. ALDH isozyme II was found in most of the tissues and erythrocytes. A higher frequency of individuals possessing lower ALDH activity in hemolysates was observed in alcoholics than that in controls. The activity of acid phosphatase was also reduced in alcoholics. Alcohol abuse might result in disturbed protein synthesis in the erythrocytes.

Liver glutathione S-transferase polymorphism in Japanese and its pharmacogenetic importance

SummaryA total of 168 autopsy liver extracts from Japanese individuals were examined for the glutathione S-transferase (GST) isozymes by means of starch gel electrophoresis. The gene frequencies of GST1*1, GST1*2, and GST1*0 in Japanese were 0.252, 0.057, and 0.691, respectively. GST1*3 was detected as a rare variant allele. The incidence of GST1 0 in 41 liver biopsy samples from patients suffering from various liver diseases was investigated using polyacrylamide gel isoelectric focusing. The GST1 0 phenotype was found more frequently in livers with hepatitis and carcinoma than in control livers. The isozymes coded by different GST loci were partially purified and characterized to study their biochemical properties. The apparent Km values with 1-chloro-2,4-dinitrobenzene (CDNB) as substrate for the isozymes at the GST1, GST2, GST3, and GST4 loci were 604, 1345, 776 and 591 μM, respectively.

Genotyping of mitochondrial aldehyde dehydrogenase in blood samples using allele-specific oligonucleotides: comparison with phenotyping in hair roots

SummaryDeficiency of mitochondrial aldehyde dehydrogenase (ALDH I) is an inborn error of metabolism that is responsible for acute alcohol sensitivity (flushing response) observed only in Orientals of Mongoloid origin. Our previous studies using electrophoretic enzyme detection have shown that this deficiency is prevalent among Japanese, Chinese, and other Orientals. We report here the genotyping of ALDH I locus in blood samples of 218 South Korean individuals by means of hybridization analysis with allele-specific oligonucleotide probes and enzymatically amplified human genomic DNA. The results of genotyping are compared with the phenotype analysis in hair roots of the same individuals. Among 62 apparently deficient phenotypes, 58 heterozygote and 4 homozygote deficient genotypes were observed.

Inheritance of mitochondrial aldehyde dehydrogenase: genotyping in Chinese, Japanese and South Korean families reveals dominance of the mutant allele

SummaryGenotyping of mitochondrial aldehyde dehydrogenase (ALDH I) was performed in enzymatically amplified DNA of 20 Chinese, Japanese and South Korean families (85 individuals) and in 113 unrelated persons by employing allele-specific oligonucleotide probes and dot blot hybridization. Genotyping individuals with phenotypic deficiency of ALDH I activity always showed the presence of at least one mutant allele. The data are compatible with a model assuming dominant inheritance of the mutant allele, which we have previously suggested on the basis of a population study.

Comparative study of erythrocyte aldehyde dehydrogenase in alcoholics and control subjects.

Human erythrocyte aldehyde dehydrogenase (ALDH, EC 1.2.1.3) shows a single activity band on starch gel electrophoresis and isoelectric focusing in polyacrylamide gel (pI = 5.0-5.3). The erythrocyte enzyme is identical with the slower migrating, disulfiram-sensitive human liver ALDH isozyme II. Significantly decreased activity of erythrocyte ALDH was observed in chronic alcoholics when compared with healthy controls and non-alcoholic psychiatric and gastrointestinal patients. The measurement of ALDH in erythrocyte lysates may offer yet another sensitive and specific biochemical marker of alcoholism.

Human liver alcohol dehydrogenase isoenzyme variations

SummaryHuman liver alcohol dehydrogenase isozyme patterns were studied using prolonged high voltage starch-gel electrophoresis and gel-slab isoelectric focusing. Homo- and heterodimers of ADH2 locus were easily distinguished from each other. The gene frequencies of ADH22and ADH32in 46 random liver samples from Germany were found to be 0.044 and 0.424 respectively.

Human aldehyde dehydrogenases: their role in alcoholism

This article surveys the state of our knowledge concerning the biochemical and genetic variations in aldehyde dehydrogenases (ALDHs) in humans and their role in alcohol sensitivity, alcohol drinking habits, and alcoholism. Variations in acetaldehyde metabolism via genetically determined polymorphisms in ALDH enzymes seem to play an important role in individual and racial differences in acute and chronic effects of alcohol drinking as well as towards vulnerability to organ damage after chronic alcohol abuse. Alcohol sensitivity and associated discomfort symptoms accompanying alcohol ingestion may be determinantal for the significantly low incidence of alcoholism among Japanese, Chinese and other Orientals of Mongoloid origin. An abnormal ALDH isozyme has been found to be widely prevalent among individuals of Mongoloid race, and is mainly responsible for the acute sensitivity to alcohol commonly observed in this race. Persons sensitive to alcohol by virtue of their genetically controlled ALDH isozyme deficiency may be discouraged from drinking large amounts of alcohol in their daily life due to the initial adverse reaction experienced after drinking alcohol, and thus are protected against alcoholism.

Pharmacogenetics of alcohol dehydrogenase (ADH)

There are many contributing factors in the metabolism of ethanol in humans. Alcohol dehydrogenase (ADH) plays a major and important role in the oxidation of ethanol to acetaldehyde in various organs and tissues. This article deals with biochemical and genetic findings regarding the enzymatic degradation of ethanol in humans with particular emphasis on the properties and role of the ADH enzyme

Evidence for a signal peptide at the amino‐terminal end of human mitochondrial aldehyde dehydrogenase

A full‐length cDNA clone coding for human mitochondrial aldehyde dehydrogenase (ALDH 1) was isolated from a human fetal muscle cDNA library. Sequence analysis revealed structural similarities between the amino‐terminal end of ALDH I and other known targeting sequences responsible for protein uptake into the mitochondria.