Karino K, Kador P F, Berkowitz B, Balaban R S
National Eye Institute, Laboratory of Mechanism of Ocular Disease, National Institutes of Health, Bethesda, Maryland 20892.
J Biol Chem. 1991 Nov 5;266(31):20970-5.
In the present study we have determined the kinetics of 3-deoxy-3-fluoro-D-glucose (3-FG) as a substrate for the aldose reductase reaction in vitro. In addition, we compared the 3-deoxy-3-fluoro-sorbitol (3-FS) production rates from 3-FG in the intact lens using 19F NMR with conventional aldose reductase determinations in extracts from the same lenses. The affinity of in vitro aldose reductase for 3-FG was approximately 20 times greater (9.3 mM) than that for glucose (188 mM). An excellent correlation between the rate of 3-FS production in the intact canine lens, determined with 19F NMR, and extracted aldose reductase activity was observed. The relatively high affinity of aldose reductase for 3-FG and the correlation of 3-FS production with enzyme activity in the intact lens suggests that 3-FS production from 3-FG detected by 19F NMR could provide an accurate noninvasive determination of aldose reductase activity in the eye lens.
在本研究中，我们测定了3-脱氧-3-氟-D-葡萄糖（3-FG）作为体外醛糖还原酶反应底物的动力学。此外，我们使用19F核磁共振（19F NMR）比较了完整晶状体中由3-FG生成3-脱氧-3-氟山梨醇（3-FS）的速率，以及同一晶状体提取物中常规醛糖还原酶测定的结果。体外醛糖还原酶对3-FG的亲和力（9.3 mM）约为对葡萄糖（188 mM）的20倍。通过19F NMR测定的完整犬晶状体中3-FS生成速率与提取的醛糖还原酶活性之间存在良好的相关性。醛糖还原酶对3-FG的相对高亲和力以及完整晶状体中3-FS生成与酶活性的相关性表明，通过19F NMR检测到的由3-FG生成3-FS的过程可提供一种准确的、非侵入性的测定眼晶状体中醛糖还原酶活性的方法。
