Tottmar O, Hellström E
Pharmacol Biochem Behav. 1983;18 Suppl 1:103-7. doi: 10.1016/0091-3057(83)90154-5.
The characteristics of human blood aldehyde dehydrogenase with indole-3-acetaldehyde as the substrate were investigated. Blood volumes of less than 25 microliter could be assayed. The Km-value was below 10 microM for indole-3-acetaldehyde and 100 microM for NAD+. The ALDH-activity appeared to be located exclusively in the intracellular fraction of the erythrocytes. Acetaldehyde or ethanol at concentrations up to 1 and 40 mM respectively did not affect the activity. Disulfiram caused a pronounced inhibition of the enzyme both in vitro and in vivo. The blood ALDH-activity in disulfiram-treated patients was not fully restored until 6 weeks after discontinuation of the treatment. The inhibition observed in vitro was reversed completely by 2-mercaptoethanol but only partially by glutathione. No restoration of activity in blood from disulfiram-treated patients was obtained with these two reagents. The inhibition found in vitro and in vivo was more pronounced when the assays were performed with indole-3-acetaldehyde than with acetaldehyde. The results suggest that different isozymes of ALDH are involved in the assay with these two substrates.
研究了以吲哚 - 3 - 乙醛为底物的人血醛脱氢酶的特性。可测定小于25微升的血量。吲哚 - 3 - 乙醛的Km值低于10微摩尔，NAD⁺的Km值为100微摩尔。醛脱氢酶活性似乎仅存在于红细胞的细胞内部分。乙醛或乙醇浓度分别高达1和40毫摩尔时不影响该活性。双硫仑在体外和体内均对该酶有明显抑制作用。双硫仑治疗患者的血醛脱氢酶活性在停药后6周才完全恢复。体外观察到的抑制作用可被2 - 巯基乙醇完全逆转，但仅被谷胱甘肽部分逆转。这两种试剂不能使双硫仑治疗患者的血液恢复活性。当用吲哚 - 3 - 乙醛进行测定时，体外和体内发现的抑制作用比用乙醛时更明显。结果表明，醛脱氢酶的不同同工酶参与了这两种底物的测定。
