Tanimoto T, Sato S, Kador P F
National Eye Institute, National Institutes of Health, Bethesda, MD 20892.
Biochem Pharmacol. 1990 Feb 1;39(3):445-53. doi: 10.1016/0006-2952(90)90049-q.
Engelbreth-Holm-Swarm (EHS) tumor cells were utilized as a model for investigating the production of basement membrane components. These cells contain two immunologically distinct NADPH-dependent reductases, aldose reductase (EC 1.1.1.21) and aldehyde reductase (EC 1.1.1.2), which were purified to apparent homogeneity by a combination of procedures which included ammonium sulfate fractionation, Sephadex G-75 gel filtration, Matrex Gel Orange A affinity chromatography, and chromatofocusing on Pharmacia Mono P. The molecular weights of aldose and aldehyde reductases were estimated to be 38K and 40K, respectively, by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Substrate specificity studies showed that both enzymes were capable of reducing a variety of aldehydes to their respective alcohols; however, only aldehyde reductase oxidized L-gulonic acid. Surprisingly, both enzymes showed similar reactivities with D-glucose and D-galactose, suggesting that both aldose and aldehyde reductases may contribute to sorbitol production in the EHS tumor cell. The activities of both enzymes were increased by the presence of sulfate ion, but chloride ion decreased the activity of aldose reductase. Both aldose and aldehyde reductases were inhibited by a series of structurally diverse aldose reductase inhibitors.
恩格尔布雷特-霍尔姆-斯旺（EHS）肿瘤细胞被用作研究基底膜成分产生的模型。这些细胞含有两种免疫上不同的NADPH依赖性还原酶，醛糖还原酶（EC 1.1.1.21）和醛还原酶（EC 1.1.1.2），通过包括硫酸铵分级分离、Sephadex G-75凝胶过滤、Matrex Gel Orange A亲和色谱以及在Pharmacia Mono P上进行色谱聚焦等一系列步骤，将它们纯化至表观均一性。通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳估计醛糖还原酶和醛还原酶的分子量分别为38K和40K。底物特异性研究表明，这两种酶都能够将多种醛还原为各自的醇；然而，只有醛还原酶能氧化L-古洛糖酸。令人惊讶的是，这两种酶对D-葡萄糖和D-半乳糖表现出相似的反应性，表明醛糖还原酶和醛还原酶都可能在EHS肿瘤细胞中参与山梨醇的产生。硫酸根离子的存在会增加这两种酶的活性，但氯离子会降低醛糖还原酶的活性。这两种酶都受到一系列结构各异的醛糖还原酶抑制剂的抑制。
