Kichihei Yamasawa

Purification and partial characterization of aldehyde dehydrogenase from human erythrocytes

Human erythrocyte aldehyde dehydrogenase (aldehyde:NAD+ oxidoreductase, EC 1.2.1.3) was purified to apparent homogeneity. The native enzyme has a molecular weight of about 210,000 as determined by gel filtration, and SDS-polyacrylamide gel electrophoresis of this enzyme yields a single protein and with a molecular weight of 51,500, suggesting that the native enzyme may be a tetramer. The enzyme has a relatively low Km for NAD (15 microM) and a high sensitivity to disulfiram. Disulfiram inhibits the enzyme activity rapidly and this inhibition is apparently of a non-competitive nature. In kinetic characteristic and sensitivity to disulfiram, erythrocyte aldehyde dehydrogenase closely resembles the cytosolic aldehyde dehydrogenase found in the liver of various species of mammalians.

Metabolism of acetaldehyde by human erythrocytes

Abstract Acetaldehyde metabolism in human erythrocytes was studied using head-space gas chromatographic determination methods, and it was found that acetaldehyde is metabolized in erythrocytes by NAD dependent cytosolic enzyme having an apparent Km value for acetaldehyde approximately 0.7 mM at pH 7.4, and more than 50% of this activity was reduced by 1 μM disulfiram. So, it is suggested that erythrocytes may have an enzyme system similar to the high Km isozyme of the liver aldehyde dehydrogenase.

Genetic Polymorphism of Plasminogen: A New Basic Variant (PLG B) and Population Study in Japanese

Abstract. Genetic polymorphism of human plasminogen in the Japanese population was studied using agarose gel isoelectric focusing followed by immunofixation. A new basic variant, PLG B, was found as a heterozygous state PLG l‐B, which was genetically determined. The allele frequencies calculated from 258 individuals were PLG1=0.958, PLG2=0.020 and PLGB=0.022.

Genetic polymorphism of the B subunit of human coagulation factor XIII: Another classification

SummaryGenetic polymorphism of the B subunit of human coagulation factor XIII was studied using agarose gel isoelectric focusing (pH 4–6.5) followed by immunofixation. Factor XIII-B of all samples after desialylation was classified into three types (F, S, and FS). From results of the present study, it was confirmed that factor XIII-B was controlled by two codominant alleles on an autosomal locus. Allele frequencies of F-XIIIBF and F-XIIIBS in a Japanese population were 0.336 and 0.664, respectively.

Effects of disulfiram and its reduced metabolite, diethyl-dithiocarbamate on aldehyde dehydrogenase of human erythrocytes

Inhibition of human erythrocyte aldehyde dehydrogenase (ALDH) activity was studied using disulfiram and its reduced metabolite, diethyldithiocarbamate (DDC). The enzyme was rapidly inactivated by disulfiram and the inhibition was protected by reduced glutathione (GSH), in a concentration dependent manner when the enzyme premixed with GSH was reacted with disulfiram. Higher reactivity of the thiol group of the enzyme than that of GSH to disulfiram was suggested from the observation that half of the enzyme activity was inhibited when the ratio of disulfiram to GSH was 1:10. Although DDC alone showed no inhibitory effect on the enzyme, inactivation was mediated by a low concentration of heme-containing peroxidases, but not by methemoglobin. Under this condition, the inhibition potential was not protected, even with a high concentration of GSH. The constant reoxidation system of DDC is probably directly related to the enzyme inactivation.

Three New Variants in the Plasminogen System

Three new phenotypes of plasminogen system, named PLG 3-1, PLG 1-M and PLG 1-C, were found in sera from healthy Japanese persons by the agarose gel isoelectric focusing followed by the methods of immunofixation and caseinolysis. The present study indicates that at least the PLG 3 component is genetically determined. The existence of another PLG3 allele is postulated.

Phenotypic variation of human antithrombin III in normal plasma: Detection by isoelectric focusing

SummaryPlasma AT-III exhibits a microheterogeneous form with pIs distributed over a narrow pH range by analytical agarose gel isoelectric focusing followed by immunofixation. Three new variants, each of which was the heterozygous state between the common and each variant components, were observed in a total 370 samples from unrelated healthy donors. These variants have at least normal activities of the thrombin inactivation in the presence of heparin, and their immunological antigen concentrations in plasma are in the normal range.

Genetic polymorphism of white blood cell glucose dehydrogenase in Japanese

SummaryGenetic polymorphism of the glucose dehydrogenase in white cells extracts from random adult Japanese was investigated using polyacrylamide gel isoelectric focusing or agarose gel isoelectric focusing, followed by a specific zymogram technique. Three common phenotypes, which might correspond to GDH 1, GDH 2 and GDH 2-1 reported by King and Cook (1981), were observed at the p Is between pH 6.56–6.76 on the gel. No phenotypes with GDH 3 component were detected so far. The allele frequency of GDH3 may be very low among Japanese. The results of family study suggest that these phenotypes are inherited in the autosomal codominant trait. The allele frequencies were GDH1=0.522 and GDH2=0.478.

Comparative Study of Phenotypes on Activity and Plasma Concentration in the Genetic System of Plasminogen

Plasma antigen concentration of plasminogen was approximately 11-13 mg/100 ml in all phenotypes. Specific activities of common PLG 1-1 and second common PLG 2-1 were 16.52 +/- 1.43 U/mg (caseinolytic activity/milligram antigen concentration, mean +/- SD) and 17.22 +/- 2.14 U/mg, respectively. Caseinolytic activity, antigen concentration and specific activity of PLG 1-B were 0.80 +/- 0.23 U/ml, 11.39 +/- 2.44 mg/100 ml and 6.95 +/- 0.96 U/mg. Plasma plasminogen levels of three rare phenotypes (PLG 3-1, PLG 1-C and PLG 1-M) were at least in the normal ranges by immunological and biological assay.

Relationship between human erythrocyte aldehyde dehydrogenase and sensitivity to alcohol

treatment inhibits the degradation of proteins in regenerating rat liver. During chronic treatment this stabilization may overcome the inhibitory effect seen in the beginning of the regeneration in the activities of ODC and TAT causing the accumulation of enzyme proteins during regeneration. These results, which are in accordance with previous reports on the pathological accumulation of proteins after longer ethanol treatment both in normal and in regenerating rat liver, suggest that ethanol-induced stabilization can be a reason for the accumulation. Regenerating liver appears to be a suitable model to study the mechanisms responsible for this accumulation because the changes in rate of protein synthesis and degradation are produced very rapidly by ethanol treatment.